home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Magnum One
/
Magnum One (Mid-American Digital) (Disc Manufacturing).iso
/
d3
/
ks20_2.arc
/
KS.DOC
< prev
next >
Wrap
Text File
|
1990-12-16
|
98KB
|
2,279 lines
KWIKSTAT 2.00
Condensed Manual on Disk
Statistical Data Analysis
for IBM PC and Compatible Computers
by Alan C. Elliott
TexaSoft/Mission Technologies
P.O. Box 1169
Cedar Hill, Texas 75104
214-291-2115
Version 2.00
(C)Copyright 1989 Alan C. Elliott
ALL RIGHTS RESERVED
All rights reserved. Printed in the United States of America. No part
of this book may be reproduced without prior permission. For
information, address TexaSoft, P.O. Box 1169, Cedar Hill, Texas 75104.
No patent liability is assumed with respect to the use of the
information contained herein. While every precaution has been taken in
the preparation of this publication, the publisher assumes no
responsibility for errors or omissions. Neither is any liability
assumed for damages resulting from the use of the information herein.
___________________________________________________________
Please become a registered user - send in ORDER form.
1
KWIKSTAT 2.00
___________________________________________________________
ORDER BLANK FOR KWIKSTAT
DISTRIBUTOR SN:K200689
KWIKSTAT software package, bound manual, latest version
registration, diskettes ($49) x _______= $____________
KWIKSTAT 10-PACK - Ten full copies ($299) x _______= $____________
KWIKSTAT Manuals ($10 each) x _______= $____________
(You must be a registered user to order manuals)
Automatic KWIKSTAT update to next future version,
disks and manual ($25) x _______= $____________
Printer support disk for users with Hercules (Monographics)
monitors and/or Laserjet/Paintjet ($5) x _______= $____________
Add $4 Postage & Handling or $8 if PO, COD or RUSH, $____________
$15 for Express Mail or add $10 if overseas.
Texas Residents add 7% sales tax $____________
TOTAL ENCLOSED $
============
-------------------------------------------------------------------
Specify: ____5 1/4 inch disk or ____ 3.5 inch disk
-------------------------------------------------------------------
Check one:___Check or M.O. ___MC ___VISA ___ P.O. #___________
-------------------------------------------------------------------
IF CREDIT CARD:Name on card:_________________________________
Card Number is:____________________________Exp Date__________
Authorized Signature:________________________________________
-------------------------------------------------------------------
Mail order to:____________________________________________
Address:__________________________________________________
City, State, Zip:_________________________________________
Phone ( )______________________________________________
-------------------------------------------------------------------
Mail to:TexaSoft, P.O. Box 1169, Cedar Hill, TX 75104. Thanks!
Guaranteed satisfaction or return for a full refund. Phone Orders
(Visa, MasterCard): Call 214-291-2115. ORDER NOW!
___________________________________________________________
Please become a registered user - send in ORDER form.
2
KWIKSTAT 2.00
___________________________________________________________
INSTALLING KWIKSTAT
KWIKSTAT is distributed on two diskettes, Disk 1 and Disk 2. These
diskettes contain the KWIKSTAT programs and supporting files.
REQUIREMENTS TO RUN KWIKSTAT
1. An IBM PC or compatible computer.
2. DOS 2.0 or higher.
3. At least 320K of memory.
4. A graphics, CGA, EGA, VGA or Hercules graphics type monitor. (If
you have a standard monochrome (IBM type) screen, the calculated
results will still be ok, but the graphics will not be displayed.)
INSTALLING KWIKSTAT ON YOUR HARD DISK
A hard disk is recommended for using KWIKSTAT, although individual
programs can be run from a floppy disk. The procedure described here
loads KWIKSTAT on the hard disk drive C:, in a subdirectory named
C:\KWIKSTAT.
STEP 1: Place the KWIKSTAT disk number 1 in drive A:. Make disk A: the
default drive, by entering the command:
C>A:
Next, enter the command:
A>KWIKLOAD C:
Follow the instructions on the screen, and all necessary files will be
loaded. If you want the program loaded on a hard disk other than C:,
place the disk drive name (e.g. D:) in the KWIKLOAD command in place
of the C:.
STEP 2: In order to print a graphics plot to the printer, the DOS
command file GRAPHICS.COM must be loaded into memory. (Hercules
graphics may require a special print program. See information in the
appendix of this manual.) The command GRAPHICS is in the KS.BAT file
used to begin KWIKSTAT. In order for DOS to know where to find the
GRAPHICS.COM command, you must place a PATH command in your
AUTOEXEC.BAT file that points to the directory where the GRAPHICS
command resides.
FOR FLOPPY DISK OPERATION
KWIKSTAT modules (.EXE) programs may be run independently, as long as
the runtime module (BRUN40.EXE) is also on disk. If you are using a
floppy-disk based system, you may generally put three or four KWIKSTAT
programs on a disk. The programs are named KS20????.EXE, where ???? is
DATA, STAT, AOV1, REG, CROS, LIFE and UTIL. Copy the most used
programs, and the files KSMENU.INI and KWIKSTAT.HLP on a diskette
___________________________________________________________
Please become a registered user - send in ORDER form.
3
KWIKSTAT 2.00
___________________________________________________________
along with the BRUN40.EXE and copy the remaining programs on another
diskette.
When running KWIKSTAT on floppies, place the program disk in drive A:
and the data disk in B:. In the UTILITIES module, set up your default
path to B:\. This will create a file called "KSTAT.INI". From DOS,
copy that file to your other program disk. The KSTAT.INI file tells
KWIKSTAT where your data is stored. While running KWIKSTAT you will
never need to change disks unless you attempt to run a program that is
not on the default disk. When you want to run such a program, KWIKSTAT
will prompt you to switch disks. You will not have to change the data
disk in drive B:. Never change the data disk while a KWIKSTAT program
is running.
If you are using a 3.5 inch disk or a 5 1/4 inch 1.2 megabyte disk
system, you can fit all of the KWIKSTAT programs on one disk.
INSTRUCTIONS FOR OPERATION
From the hard disk prompt "C", get into the KWIKSTAT directory using
the command:
C>CD \KWIKSTAT
To begin KWIKSTAT, enter the command:
C>KS
MONITOR AND PATH SETUP
To setup KWIKSTAT for the monitor you are using, and for the path to
your data, select the SETUP option in the UTILITY module, and select
the appropriate choice for the path to your data.
LATENEWS
Print the file LATENEWS.DOC to get the latest information on Kwikstat.
It may include information on new features or changes not included in
this manual.
A KWIK TUTORIAL
This short tutorial will give you a feeling for how to use KWIKSTAT.
It will assume you are using KWIKSTAT on a hard disk. Begin KWIKSTAT
with the KS command. After the intro screen, notice the menu.
Items lettered A to I are procedures of THIS module. Items numbered 1
to 7 are additional modules. Items 1 to 7 will always stay the same.
Lettered menu items change depending which module you are currently
using.
___________________________________________________________
Please become a registered user - send in ORDER form.
4
KWIKSTAT 2.00
___________________________________________________________
THE HELP SCREEN
To examine the HELP menu, press the F1 function key. The HELP menu
lists major topics, and the screen number. To look at a particular
topic, enter the screen number you desire. For example, look at screen
7. Type the number 7, and press Enter:
Enter SCREEN NUMBER or Enter to Cancel:7
KWIKSTAT displays screen 7. To move to screen number 8, press Enter.
To go back to the menu, type the "M" key. To exit the HELP module,
press the "Esc" key. Press the Esc key now. This takes you back to the
main KWIKSTAT DATA module menu. Every module has the help screens
available. The help facility is always selected from a KWIKSTAT main
menu, by pressing F1.
EXAMPLE OF DESCRIPTIVE STATISTICS
This example will use data already stored in a dBASE ".DBF" file
currently on the KWIKSTAT disk. To go to the Descriptive Statistics
"STAT" module, type 1 at the DATA module menu. It takes a few seconds
to swap modules. Soon, you will see an initial screen which gives a
directory of all ".DBF" files on disk. The program prompts you to
choose the database to use. For this example, enter the name EXAMPLE.
KWIKSTAT will usually "remember" the last database you used, and will
automatically read in that database when a module is begun. In this
case, choosing a database is skipped, and you immediately go to the
main module menu. Enter dBASE III file to use (.DBF assumed):EXAMPLE
KWIKSTAT will load the file, and present the Descriptives Statistics
menu. (NOTE:There are some procedures which do not require input from
a database. By entering a blank name, you may proceeded with no
database in use.) If KWIKSTAT does not find the EXAMPLE database, you
may not be in the KWIKSTAT subdirectory, or you may not have loaded
KWIKSTAT correctly. If so, return to the installation instructions and
try again.
From the STAT menu, press the letter B to choose Descriptive
Statistics. The program now displays the variables available for
analysis from the database. In the variable selection menu only the
numeric variables are available, since it doesn't make sense to find
the mean of a character variable.
Enter the number 2 to select the AGE variable, and press Enter. The
program will now perform a series of calculations on the data, and
will produce a screen of descriptive statistics, and a box plot of the
data.
If you want a printed copy of this screen, MAKE SURE YOUR PRINTER IS
TURNED ON, and is ON LINE, and HAS PAPER. Then, press Shift-Prtsc.
Notice that this is a graphics screen, and generally takes longer to
print than a normal screen. Any time you want a copy of the results on
___________________________________________________________
Please become a registered user - send in ORDER form.
5
KWIKSTAT 2.00
___________________________________________________________
the screen, use the Shift-Prtsc command (some versions of the PC
keyboards have a print screen command that does not require a shift).
IF THE SCREEN DOES NOT PRINT PROPERLY: You may not have the GRAPHICS
command properly implemented - see installation again. Check your
printer manual and the appendix on printers and monitors.
To return to the main menu, press the Esc key. From the main menu, to
end KWIKSTAT and return to DOS, press Esc. Optionally, you could have
swapped to any other KWIKSTAT module. This ends the brief tutorial.
IF SOMETHING GOES WRONG
If something goes wrong, check the manual, and check your work. If you
cannot seem to resolve the problem, please fill out the BUG REPORT in
the appendix, and send it in right away, so that errors in the program
can be eliminated. If you have a suggestion for how to improve
KWIKSTAT, please fill out the USER'S BALLOT in the appendix. Thanks.
ERROR CODES
The KWIKSTAT program is written in QuickBASIC, a Microsoft Product.
When error codes appear, you may often look these codes up in the
Appendix of your IBM or Microsoft BASIC manual. Some error codes are
given in an appendix to this manual. Sometimes an error is caused by
something that is easy to fix, such as a full disk, or a write protect
tab on a disk. If it looks like a program bug, PLEASE fill out a bug
report form, and mail it in.
KWIKSTAT DATA MODULE
The KWIKSTAT data module (KS20DATA.EXE) is used to manage your data.
In this module you enter data, change data, create new data fields
from existing ones, and perform other data maintenance tasks. Once
your data is in the KWIKSTAT (dbase III-type) database, you can access
it from any of the other KWIKSTAT modules. Some of the KWIKSTAT
procedures require that you have data in a file before you can do an
analysis. Other procedures allow you to enter information from the
keyboard at the time you request the procedure. Some procedures give
you an option to enter data from a database, or from the keyboard.
Compatibility With Dbase III
A KWIKSTAT database uses the same file format as the dBASE III
program. Therefore, data already stored in a dBASE III file may be
read directly into all the KWIKSTAT programs.
___________________________________________________________
Please become a registered user - send in ORDER form.
6
KWIKSTAT 2.00
___________________________________________________________
THE DATA MODULE MENU
Details on Specific Procedures
The following explanation describes the options within the DATA
module.
A) CREATE A NEW DATABASE STRUCTURE
The CREATE option is used to create a new database. The structure, or
layout, of a database must be described before you enter your data.
You need to give some thought to how your database will "look" so it
will be in the proper format to do the analysis you desire.
Do You Need a Grouping Variable?
If you have information on several groups, you should have a grouping
variable as a part of your database. A grouping variable could be
either character (e.g. A,B,C etc) or numeric (e.g. 1,2,3, etc). If you
may subset your database in the future, use numbers for grouping
variables, since subsetting requires comparisons of numeric variables
to work. See the example analyses for help in setting up your database
Name Your Database
When you choose the A option, the program will ask you to specify a
name for the database. The name may be up to 8 characters in length,
DO NOT include an extension to the name, and the name should obey DOS
naming conventions. (Do not use blanks, commas, periods, slashes, etc.
in the name.)
The extension ".DBF" will be assigned to the database file name. Once
you have named the database, you will define the fields -- names of
the places where the data will be stored. Name your variable in such a
way to make the name descriptive. Names may be up to 10 characters in
length. For example, if age is one of the pieces of data you
collected, name that variable AGE. Other example names might be
WEIGHT, GROUP, SYSBP, etc.
In order for you to name each field, and to tell KWIKSTAT how much
space to allocate for storing the information, KWIKSTAT will display
highlighted areas to enter Name, Type, Width, and number of Decimal
places for each field in the database structure, as illustrated D.2.
Define the Fields in Your Database
When you first enter the definition mode, the blinking cursor will be
in the FIELD NAME area. Enter a name, and press the ENTER key. The
name you choose will be displayed in all capital letters, and the
cursor will move to the next area, TYPE.
In the TYPE area, you only need to enter the first character of the
___________________________________________________________
Please become a registered user - send in ORDER form.
7
KWIKSTAT 2.00
___________________________________________________________
type, (N, C, L or D), then press the ENTER key. If your choice is
NUMERIC, simply press ENTER when your cursor moves to this area, as
this is the default TYPE. The cursor moves to the WIDTH area, unless
TYPE is Logical or Date. KWIKSTAT allows you to define Logical and
Date variables, but it will only read and use Numeric or Character
type variables.
WIDTH is the number of characters reserved for the entry. Decimal is
the number of decimal places (only relevant for numbers). The number
of decimal places must be at least one less than the width. For
example, if a number has the format ###.##, the width is 6 (count the
decimal point), and the number of decimal places is 2. If DATE or
LOGICAL is entered as type, the program will automatically assign a
width of 8 or 1 respectively.
Once a complete field description is entered, a next blank field
description will appear, ready for entry. To end the creation process,
type Control-END (^END). The End key is on the numeric pad. As long as
you have not ended the procedure, you may use the cursor keys to back
up, and make any corrections.
If you mess up, end the procedure with Esc and begin again. After
entering information, press CTRL-End (^End) to exit and save the
created database.
If you want to enter data from the keyboard, answer "Y" to the
question
ENTER DATA FROM KEYBOARD NOW (Y/N)
Otherwise answer "N". You can always enter the data later, or add to
data already in a database.
TYPES OF DATABASE FIELDS
1. The FIELDNAME:A fieldname must be 1 to 10 characters in length and
MUST begin with a character (a to z). Upper and lower case DO NOT
matter, since the name is always translated into all upper case.
2. The TYPE:Type may be
CHARACTER - May contain any character.
NUMERIC - Must contain numbers only.
DATE or LOGICAL fields can be created, but KWIKSTAT will only use
Numeric and Character fields.
3. The WIDTH of the field: Choose a width so that the maximum number
of characters will fit into the field.
4. DECIMALS:Decimals are only valid for numeric fields. This specifies
___________________________________________________________
Please become a registered user - send in ORDER form.
8
KWIKSTAT 2.00
___________________________________________________________
to KWIKSTAT how many decimals to retain in the field.
LIMITATIONS TO THE KWIKSTAT DATABASE:
Maximum of 128 fields.
Maximum width of a field name is 10 characters.
Maximum width of a cell is 60 characters (15 for numbers)
Dates are always 8 characters and logical fields are 1 characters
wide.
B) ENTER DATA - INPUT DATA FROM KEYBOARD OR ASCII FILE
When you choose this option, you will be asked to specify entry from
the keyboard or from a file (ASCII file). For most small data sets,
you will probably enter data from the keyboard. If you choose to enter
data from the keyboard, an entry screen will appear containing the
fields you created in the CREATE option. Enter data in the same way
the field descriptions were entered. If you need to go back to a
previously entered record to edit, pressing the PgUp key will
automatically place you into edit mode. To end keyboard entry, press
^End. If the number of fields is too many to be displayed on one
screen, you may use the Up and Down arrow keys to reveal the following
pages of entry fields.
If you choose to enter data into a database from a file (or to append
data to an already existing database), you will be asked the name of
the raw data file. As will be described later in detail, the data in
the file must match the database structure.
The data will be entered into the database, and a count of the records
as they are entered will be displayed. It is a good idea to go to the
KWIKLIST procedure to look at the data to verify that it has been
entered correctly, or print the data out using the UTILITIES module
report option. If the data does not match the fields, refigure the
widths of each field to make sure it matches the columns of data in
the disk file, and try again.
C) EDIT RECORDS IN THE DATABASE
If there is a need to change data already in a database, you may
choose the EDIT option. You will be asked for the name of the
database, and the specific record number you wish to edit. Once in the
EDIT mode, you may use the PgUp and PgDn keys to move to records
before or past the one you are currently editing. If you are entering
data, and press the PgUp key, the program automatically places you in
edit mode.
In the edit mode, you may specify that certain records are marked for
delete. This is done by typing a ^U (CTRL-U) while you are editing a
specific record. A **DEL** will appear on the screen of a deleted
record. Often in procedures, specifically in REPORT, you are asked if
you want the program to skip records marked for delete. In Edit,
___________________________________________________________
Please become a registered user - send in ORDER form.
9
KWIKSTAT 2.00
___________________________________________________________
deleted records may be recovered by pressing ^U a second time, and the
**DEL** mark is removed. To permanently get rid of "deleted" records,
use the Pack procedure.
D) PACK - GET RID OF DELETED RECORDS
In the EDIT mode, or in dBASE III, you may mark certain records for
delete. To permanently get rid of these records from the database,
choose the PACK procedure.
E) DISPLAY STRUCTURE OF A DATABASE
This option displays the structure of your database, as you created in
the CREATE option, or that was created in dBASE III.
F) SET MISSING VALUE CODES
Sometimes in the collection of data there are values that are lost or
cannot be gathered. These are called "missing values". Missing values
are usually designated as an impossible value. For example, the
missing values designated for the variable AGE may be -9, since it is
impossible for the variable AGE to have the value -9. When the program
is asked to calculate the mean of age, for example, it will ignore
those records where AGE is -9 in that calculation if -9 has been
specified as the missing value code.
Once you designate a missing value code for a variable, it is up to
you to make sure that this code gets placed into your database in the
proper records and fields.
A standard dBASE III file does not have a way to designate missing
values, but KWIKSTAT allows a way for you to designate these values in
this program. The "Set Missing Values" option in the DATA MODULE is
used to set up these values. When this option is selected, the program
will display an entry screen that is similar to a data entry screen.
You may enter one missing value for each field name. The missing value
must obey the definition of the field in terms of length and type.
IMPORTANT NOTE:If missing values are NOT used, and there is a blank
numeric variable in a calculation, it will be treated like the value 0
(zero), so it is important to use missing values if your data contains
such entries. Otherwise, the statistical calculations will be in
error!!
G) TRANSFORMATION - MAKE A NEW VARIABLE
You may create a new numeric variable in a database with the
transformation procedure. This procedure allows you to create this new
variable as a function of old variables. For example, if you wanted a
new variable to be the ratio of WEIGHT to HEIGHT, you could name a new
variable RATIO, and use the transformation WEIGHT/HEIGHT as the
expression to create the new variable.
___________________________________________________________
Please become a registered user - send in ORDER form.
10
KWIKSTAT 2.00
___________________________________________________________
CAREFUL ATTENTION must be paid to the definition to assure that the
calculated numbers will fit into the field width specifications. If
the calculated number is too large to fit into the field, it will be
given the missing value code. If an illegal calculation is attempted,
such as a division by 0, the result will be missing. If a calculation
includes a missing value, the result will be a missing value.
OPERATIONS ALLOWED IN A TRANSFORMATION
Mathematical operators: Add (+), Subtract (-), Divide (/),
Multiply (*) and Exponentation (^).
Following are a few examples of correct expressions, where the new
variable is called NEW, and numerical variables in the database
include AGE, WEIGHT, HEIGHT, and SCORE:
NEW = AGE/HEIGHT
NEW = SCORE^2
NEW = SUM(AGE,WEIGHT,HEIGHT,SCORE)
MATHEMATICAL FUNCTIONS SUPPORTED
Name Meaning Example
-------- -------- ----------
ABS Absolute value ABS(SCORE)
ACOS Arc Cosine ACOS(SCORE)
ASIN Arc Sine ASIN(SCORE)
ATAN Arc Tangent ATAN(SCORE)
ATAN2 Arc Tanget y/x ATAN2(y,x)
CSC Cosecant CSC(SCORE)
COS Cosine COS(SCORE)
COT Cotangent COT(SCORE)
EXP Exponentiation EXP(SCORE)
INT Integer INT(SCORE)
LN Natural Log LN(SCORE)
LOG Log base 10 LOG(SCORE)
MAX Maximum of list MAX(1,T2,3)
MIN Minimum of list MIN(1,T2,T3)
MOD MOD of number MOD(9,2) is 9 mod 2
PI PI PI = 3.14159265358979
RAND Random number number between 0 and 1
RECNO Record number database record number
ROUND Rounds a number ROUND(1.236,2)=1.24
SEC Secant SEC(SCORE)
SIN Sine SIN(SCORE)
SQRT Square root SQRT(SCORE)
SUM Sum of list SUM(1,2,3) = 6
TAN Tangent TAN(SCORE)
___________________________________________________________
Please become a registered user - send in ORDER form.
11
KWIKSTAT 2.00
___________________________________________________________
H) SUBSET - CREATE NEW DATABASE BY SUBSET SELECTION
This option allows you to create a new database from an old one.
For example, suppose you have a database with a field GROUP with
values 1, 2, 3, 4 and 5. You want to create a database that does NOT
include Group 5. For example, your new database might be named
NO5.DBF. You are asked for the field name to be used in the selection
criteria. In this case, you would choose the field named GROUP. Next
you must enter the selection relationship. It will be described as a
numerical expression. The conditional operators you may use are:
= > < >= <= <> = and the logical operator .NOT.
The program will prompt you with
SELECT IF GROUP
and you must finish the selection criteria. For example:
SELECT IF GROUP .NOT. = 5
(Select records for which the variable GROUP is not equal to 5.) You
may use any of the variables in the database in the expression, and
you may use the functions described in the TRANSFORMATION option.
I) LIST - KWIKLIST OF DATABASE RECORDS
KWIKLIST allows you to look at the information in your database.
Kwiklist produces a simple on screen report that lists the data one
record at a time.
DATA FROM OTHER SOURCES
KWIKSTAT can read data from a dBASE III file. To make a dBASE III
database appear in the KWIKSTAT directory, copy the .DBF file from
your dBASE III directory, or set up the path for KWIKSTAT to your
dBASE III directory. Once you have told KWIKSTAT where your dBASE III
files are, the module will display all ".DBF" files in the that
directory each time you are requested to enter a filename. However,
you may also call files from other directories using drive and path
names.
LOTUS PRODUCTS: WKS and DIF files to DBF
In Lotus 1-2-3, and other LOTUS products, there is a TRANSLATE
facility, which allows you to output data into a DBF file. The version
A1 of 1-2-3 writes out a dBASE II file, so it would need to be
DCONVERTed to dBASE III. Also, 1-2-3 can translate DIF files into the
worksheet, which can then be translated to DBF files. Lotus 1-2-3 and
other programs will output data in standard ASCII files (PRN files in
the case of 1-2-3). Using the description below on reading data from
___________________________________________________________
Please become a registered user - send in ORDER form.
12
KWIKSTAT 2.00
___________________________________________________________
an ASCII file, you can read this data into KWIKSTAT. You may have to
delete some blank or label lines from the files created by 1-2-3 to
make them into nice data files.
USING ASCII FILES
KWIKSTAT can read data from standard ASCII text files. These kinds of
files are usually supported by most word processing programs as well
as most editors. Data must be in the form of column data, like this...
A 22 3.3 WF
A 33 4.2 BF
B 27 3.3 WM
:
ETC
Use the instructions below to prepare the KWIKSTAT (dBASE) database
structure to be used to read in this data. ANY PROGRAM that can output
data in a standard ASCII text format (ie PC-FILE III, FRAMEWORK,
RBASE, etc) can be used to prepare a data file to be used by KWIKSTAT.
ALSO NOTE that KWIKSTAT can produce an ASCII text file, so that data
created in KWIKSTAT can be output, and read into other programs. (ie
dBASE, SAS, SPSS, etc). See the description of SDF files in the
UTILITY program.
Reading ASCII file data into KWIKSTAT
NOTE:There is a file on the distribution disk named EX.DAT, which
contains 50 records, and can be used to illustrate entering data from
an ASCII file.
You must be in the DATA module to enter DATA into a KWIKSTAT dBASE III
type database. Before Entering Data You Must Create The Database
Structure. Create the structure of your database by selecting the
"CREATE" option in the DATA module. (option A) You will define names
for each variable, maximum width of the field, and type of variable.
(Character, Numeric, Date, Logical). Memo fields are not supported.
If you will be entering data from an ASCII file, the field widths MUST
match the width of the columns of data on file. If there are spaces
between columns of data, make widths wide enough to account for those
spaces. The following data is from the file EX.DAT on disk:
___________________________________________________________
Please become a registered user - send in ORDER form.
13
KWIKSTAT 2.00
___________________________________________________________
A 12 22.3 25.3 28.2 30.6 5
A 11 22.8 27.5 33.3 35.8 5
B 12 22.8 30.0 32.8 31.0 4
A 12 18.5 26.0 29.0 27.9 5
B 9 19.5 25.0 25.3 26.6 5
:
etc
:
B 12 22.4 27.2 31.8 35.6 4
In this example, you would define the following fields in the CREATE
procedure. If you are actually doing this example, call the database
something other than "EXAMPLE" since there is already one named that -
suggestion: use the name "EX" for this database.
FIELD NAME TYPE WIDTH DECIMALS
----------- -------- --------- --------
GROUP C 2
AGE N 4 0
TIME1 N 5 1
TIME2 N 5 1
TIME3 N 5 1
TIME4 N 5 1
STATUS N 2
NOTE:If there are columns in the input you want to ignore, just give
them a dummy name, and call them character fields. Notice that the
GROUP field is given a width of 2, even though it is only 1 character
wide. This is to take into account the blank between the GROUP
variable and the AGE variable.
Once you have defined the database to match the ASCII input file,
choose the ENTER DATA option (B) from the DATA module menu, and choose
to read data from a file. A good check is to then use Kwiklook to
verify that the data has been entered correctly, or to print out the
entire database using the REPORT option in UTILITIES. As an example,
enter the data in EX.DAT, look at it in Kwiklist (option I), then run
some descriptives on it to see if it matches the answers given from
the EXAMPLE database.
PRINTED OUTPUT
Kwikstat has several ways of providing hard copy output of results.
Following are explanations of how each option works, and when it can
be used:
Screen Print of Text Information
To capture textual results to the printer, you may press
Shift-PrintScreen (or just Print Screen on newer keyboards) to cause a
copy of what appears on the screen to be printed to your printer.
___________________________________________________________
Please become a registered user - send in ORDER form.
14
KWIKSTAT 2.00
___________________________________________________________
Screen Print of Graphic Information
You may print a graphic screen with the Print Screen command in the
same way you print a text screen. Many of the graph screens in
KWIKSTAT have a "disappearing prompt" that allow you to get a print of
your graphic screen without the prompt appearing. Once a graph is on
the screen, wait about 5 seconds, and the prompt will disappear. Then,
issue the Print Screen command. Press Esc to exit the graph.
If you have problems getting to a graph to print, see the information
concerning Hercules/Monochrome Graphics monitors. If you have a
LaserJet or PaintJet printer, read the information in the Appendix
about printers.
Program Controlled Printing to Printer or File
A number of the Kwikstat procedures allow you to output results to the
printer in a formatted report form. The following procedures will
prompt you for printing a report version of the output to a file or
printer:
1) Analysis of Variance Results
2) Frequencies
3) Crosstabulations
4) Survival Analysis Results
5) Report Generation in Kwikstat Utilities
STATISTICS MODULES
There are five (5) modules in Kwikstat that perform statistical
analysis. These options appear on each module menu, their file names
and descriptions are:
1) KS20STAT.EXE - Descriptive Statistics and Graphs
2) KS20AOV1.EXE - t-tests, ANOVA, Non-Parametric
3) KS20REG.EXE - Simple and Multiple Linear Regression
4) KS20CROS.EXE - Crosstabs, Frequencies, Chi Square
5) KS20LIFE.EXE - Survival Analysis and Life Tables
1) DESCRIPTIVE STATISTICS AND GRAPHICS
In the descriptive statistics module (KS20STAT.EXE), you may examine
summary statistics of the data in the database. Graphics are used
throughout the system to enhance understanding of certain statistical
procedures.
Details on Specific Procedures
A) CHOOSE ANOTHER DATABASE TO USE
___________________________________________________________
Please become a registered user - send in ORDER form.
15
KWIKSTAT 2.00
___________________________________________________________
B) DETAILED STATISTICS ON A SINGLE VARIABLE - Calculates mean,
standard deviation, median, standard error of the mean, minimum,
maximum, sum, variance, Tukey 5 number summary (0, 25th, 50th, 75th
and 100th percentile), and displays a box plot of the 5 number
summary. A 95% confidence interval (C.I.) about the mean is also
displayed.
For sample sizes less than or equal to 30, a t-statistic is used to
calculate the interval. For sample sizes over 30, the 95% (two-sided)
z-statistic (1.96) is used. To print results to the printer, use the
SHIFT-PRTSC command.
C) SUMMARY STATISTICS ON A NUMBER OF VARIABLES - In this procedure,
you may choose a list of one or more variables from the database.
Statistics calculated include sample size, mean, standard deviation,
minimum, maximum, and SEM (standard error of the mean).
GROUPING FACTOR:If you have a grouping factor in your database, you
may request output of summary statistics by group. You are also given
the opportunity to print results to the printer, or to output results
to a file.
D) P-VALUE DETERMINATION - calculates a p-value for normal (Z),
Student's-t, F, or Chi-square statistic. In this procedure, enter the
request by typing the distribution symbol, and value. For example:
Enter:T(20)=2
means that you want the two-sided p-value for a calculated t-statistic
of 2 with 20 degrees of freedom. Other examples would be:
Z=1.96 Normal
F(4,8)=9.4 F-distribution (one-sided)
X(3)=4.32 Chi-Square (one-sided)
To end this procedure, enter the word END at the prompt.
E) HISTOGRAM - Produces a histogram from values read from the
database. This procedure is useful to determine if a continuous
variable approximates a normal distribution. If the histogram has a
peak toward the center, with both tails diminishing, the data could be
considered close to normally distributed.
F) SCATTERPLOT - Produces a scatterplot of two variables.
G) TIME SERIES PLOT - Produces a time-series plot from one variable.
___________________________________________________________
Please become a registered user - send in ORDER form.
16
KWIKSTAT 2.00
___________________________________________________________
EXAMPLE: DESCRIPTIVE STATISTICS
Suppose you have the following data, and you want to be able to
perform descriptive statistics such as getting means, standard
deviations, and drawing histograms and a scatterplot.
AGE WEIGHT
23 140.0
21 133.5
34 200.0
33 150.0
40 196.5
28 167.0
25 175.5
STEP 1:CREATE A DATABASE: Begin KWIKSTAT with the KS command. Select
the option from the DATA menu to CREATE a database (Option A).
STEP 2:DEFINE THE DATABASE STRUCTURE:You have two fields of data, AGE
and WEIGHT. Both are numeric. The AGE field must have at least 2
digits of width and the WEIGHT field must have 3 digits of width for
the whole number and an additional digit for the decimal. Counting the
decimal place, that means that the WEIGHT field must have at least a
width of (3+1+1)=5. As you define the database, you will enter the
following information:
FIELD NAME TYPE WIDTH DECIMALS
------------- ----- ----- --------
AGE N 2 0
WEIGHT N 5 1
That is, for the first field name enter the name AGE (does not have to
be in upper case). For TYPE enter N for Numeric. Enter 2 for the width
and 0 for number of decimals. Then, enter the information for the
variable name WEIGHT in a similar way. Notice that you allow 5 for the
width of the WEIGHT field, then specify that one digit is a decimal.
The AGE field uses no decimal places. Once you have defined the
database structure press CTRL-E to end the creation procedure, then
you may enter the data.
STEP 3: You may enter data immediately after defining the database, or
you may enter or add to the data in the database at any time using the
"Enter Data" option in the DATA module. For this example, answer Y to
the question:
Enter data from keyboard now (Y/N)?
A screen will appear that contains the names of the fields, with a
highlighted area where you may enter your data. You enter the data one
record at a time. In this case, you would enter the data 23 and 140.0,
then you will go to the next screen and enter the data 21 and 133.5 an
so on until all the data has been entered. You may end data entry two
___________________________________________________________
Please become a registered user - send in ORDER form.
17
KWIKSTAT 2.00
___________________________________________________________
ways. If you have entered these seven records, and an 8th blank record
is on the screen waiting for you to enter data, use the ESC command to
end the entry and NOT save the current (8th) record. If you are still
on the 7th record, and want to end and KEEP the 7th record, use
CTRL-END to end the entry procedure.
After ending the entry procedure, you are ready to perform your
analysis of the data.
STEP 4:Enter the Descriptives module by choosing option 1 from the
main menu. Once in the STAT module, you may choose which options to
use.
2) T-TESTS, ANOVA, NON-PARAMETRICS
The t-test, ANOVA and Non-Parametric module (KS20AOV1) performs the
following procedures:
t-test on independent groups
t-test on paired or matched data
single sample t-test
One Way Analysis of Variance on independent groups
One Way analysis of Variance on repeated data
Non-Parametric one-way ANOVA (Kruskal-Wallis) and two
group analysis (Mann-Whitney U)
Newman-Keuls multiple comparisons at the 0.05 level for all ANOVAs
Graphical comparison of groups using box plots.
Details on Specific Procedures
A) CHOOSE ANOTHER DATABASE TO USE
B) COMPARE INDEPENDENT GROUPS ANALYSIS (t-test and ANOVA)
Independent groups are observations taken from groups in which
subjects in one group do not appear in another group, nor should the
groups be related in any way. Often a large group of subjects are
split into two or more groups in a random fashion to make the required
number of sub-groups. This option allows you to print the results to
the printer in report form. After the analysis is completed, you will
be able to select output of information to the printer.
C) COMPARE REPEATED OR PAIRED DATA (t-test and ANOVA)
Repeated measures are observations taken on the same or related
subjects over time or in differing circumstances. Examples would be
weight loss, or reaction to a drug across time. Repeated measures may
also be matched subjects. This option allows you to print the results
to the printer in report form. After the analysis is completed, you
will be able to select output of information to the printer.
In this module, a t-test is performed when there are two groups (or
___________________________________________________________
Please become a registered user - send in ORDER form.
18
KWIKSTAT 2.00
___________________________________________________________
two repeated measures). For 3 to 10 groups or repeated measures, an
Analysis of Variance (ANOVA) is performed. The ANOVA attempts to
determine if there is a difference in the means across groups or
repeated measures. If the p-value for the ANOVA is small (ie 0.05 or
less), you may suspect that there is a difference. However, the ANOVA
does not tell you directly where that difference lies. See the
repeated measures example analysis that follows.
D) INDEPENDENT GROUP TESTS FROM SUMMARY DATA
This option allows you to perform a one-way ANOVA or a t-test if you
have only the means, standard deviations and group sizes of 2 to 10
groups. Since data is summary, no box plots can be given.
E) SINGLE SAMPLE T-TEST
This test allows you to choose a single variable, and test an
hypothesis that the mean of that group of data differs from a value
you choose (e.g. 0).
F) INDEPENDENT GROUP - NON-PARAMETRIC ANALYSIS
For two groups, the Kruskal-Wallis test is performed, and for 3 to 10
groups, the Mann-Whitney U test is performed. For 3 to 10 groups, a
multiple comparison test is also reported.
EXAMPLE:INDEPENDENT GROUP T-TEST
To compare two independent groups, Student's t-test for independent
comparisons can be used. If you suspect that your data may not be
normal, you should use non-parametric procedures. By independent
groups, we mean that the observed information is from different
entities - that is not the same person, plant, store etc. And that the
entities are not related.
The data used here are heights of plants grown using different
fertilizers. In order to enter this data into a database, we must
assign group numbers such as Present = Group 1 and Newer = Group 2.
___________________________________________________________
Please become a registered user - send in ORDER form.
19
KWIKSTAT 2.00
___________________________________________________________
Data for independent group t-test
------------------------------------
Present Newer
Fertilizer Fertilizer NOTE: Sizes of
------------- ---------- groups do not have
46.2 cm 51.3 cm to be equal.
55.6 52.4
53.3 54.6
44.8 52.2
55.4 64.3
56.0 55.0
48.9
-----------------------------------
A database would be created with two fields, GROUP and HEIGHT.
Reference the descriptive statistics on how to set up a database. The
data would be entered into the database as illustrated here:
GROUP HEIGHT
1 46.2
1 55.6 Notice how the grouping
1 53.3 variable tells
1 44.8 KWIKSTAT which "HEIGHT"
1 55.4 value belongs to which
1 56.0 group.
1 48.9
2 51.3
2 52.4
2 54.6
2 52.2
2 64.3
2 55.0
Notice that the GROUP field is 1 if the data are from the Present
Fertilizer group and 2 if the data are from the Newer fertilizer
group. Once the data is in a database, use Kwikstat "AOV1" module to
analyze the information. From the Kwikstat menu choose the option:
B) Compare independent groups (t-test, ANOVA)
You will be prompted by the program to indicate a grouping variable
(GROUP) and a data variable (HEIGHT). The means for each group
(1=Present 2=Newer) is displayed. A test for equality of variance
tests to see if this t-test assumption is met. A p-value greater than
0.05 indicates that you do not have a problem with this assumption. In
this case p=.4807 (no problem with inequality of variance).
The t-test is performed in two ways. If the test for equality of
variance shows no problem, use the "Equal variance" results.
Otherwise, use the "Unequal variance" results.
In this case, they are identical results. The calculated t-statistic
___________________________________________________________
Please become a registered user - send in ORDER form.
20
KWIKSTAT 2.00
___________________________________________________________
is -1.32. The test is performed with 11 degrees of freedom, and the
p-value associated with the test is 0.213. A p-value greater than 0.05
is usually interpreted to mean that there is no significant difference
in the means.
EXAMPLE: PAIRED T-TEST
To compare groups for which there are before and after measurements
for each subject or when two different measurements are made on each
of several subjects, a paired analysis is appropriate. Data for a
paired Student t-test are before an after weight for 8 persons on a
diet. Notice that in this case, both data values are taken from the
SAME entity (patient).
Data for paired t-test
Patient Before After
1 162 168 NOTE:"Group" size
2 170 136 is always equal.
3 184 147
4 164 159
5 172 143
6 176 161
7 159 143
8 170 145
Data are entered into a database with the BEFORE and AFTER measure in
each record, as illustrated here:
BEFORE AFTER
162 168
170 136
184 147
164 159
172 143
176 161
159 143
170 145
To perform this analysis in the t-tests and ANOVA module, choose the
option:
C) Compare repeated or paired data (t-test, ANOVA)
In this case, since the p-value is small (p=0.008), you conclude that
there is a statistically significant difference in the BEFORE mean
when compared to the AFTER mean. Notice that in repeated measures
there is always the same number in each group. This is because each
measure is "matched" with another one. Whereas, in the independent
t-test, you are not restricted to the same number in each group.
___________________________________________________________
Please become a registered user - send in ORDER form.
21
KWIKSTAT 2.00
___________________________________________________________
3) SIMPLE AND MULTIPLE LINEAR REGRESSION
The "REG" (KS20REG.EXE) module performs simple linear regression and
multiple linear regression.
Linear regression is used to examine the linear (straight line)
relationship between two or more variables.
Details on Specific Procedures
A) CHOOSE ANOTHER DATABASE TO USE
B) SIMPLE LINEAR REGRESSION ANALYSIS - When you choose this option
KWIKSTAT will prompt you to choose the "independent" and "dependent"
variables to be used in the analysis. The "independent" variable is
generally that variable that we can choose, regulate or specify (e.g.
amount of money spent on advertising) and the "dependent" variable is
the one you observe, and would possibly like to predict. After the two
variables are chosen, KWIKSTAT will present the results of its
calculations. The estimated linear equation will be displayed along
with other results.
The equation of the line is calculated and displayed. For example, an
equation that describes how much sales to expect given a certain level
of advertising could be:
SALES = 100 + ADV * 4.5
Therefore, you would predict sales of $100 given no advertising
(ADV=0), and with advertising in the amount of $10, we would expect
sales of about $145 (100+10*4.5). Care must be used in predicting only
values which are within the limits of the original values of the
independent variable. Outside these limits, it is only speculation
that the linear relation continues to exists. Pearson's correlation
coefficient: The correlation coefficient is a number between -1.0 and
1.0, and tells us the strength of the linear relationship between the
two variables. A correlation close to -1 or 1 means that the
relationship is strong (negative or positive), and a correlation close
to 0 means that a relationship is non-existent or very weak.
T-test for significance of slope (correlation coefficient): If the
result of the t-test is that p is small (ie less than 0.05), we can
conclude that the linear relationship is strong (statistically
significant), and that the slope of the relationship is not 0 (zero).
Scatterplots of raw data and plot of residuals from linear fit are
available, as is the ability to forecast. Plots are helpful in
visually examining the relationship between the variables. It is
important to verify that the relationship is indeed a straight line.
If it is not, a pattern should emerge from the plot of the data, or
the residuals. If the data is not linear, it could possibly be
transformed to make it linear.
___________________________________________________________
Please become a registered user - send in ORDER form.
22
KWIKSTAT 2.00
___________________________________________________________
C) MULTIPLE LINEAR REGRESSION ANALYSIS - In the multiple regression
procedure, you must enter a list of the independent variables (up to
10 variables may be used at any one time), and a single dependent
variable. A data file included on disk is named "LONGLEY". This
economic data correlates several variables with a variable called
total (total unemployment). The variable TOTAL is the dependent
variable, and the other variables are the independent variables. You
may use this database to test this procedure. Multiple linear
regression can be complicated. Refer to a good text on the subject
before making any conclusions about your results. Calculations
performed and displayed include: The coefficients and intercept to the
equation of the line are calculated and displayed. A significance test
is performed to determine their contribution to the model.
R-Square is calculated for the model, as well as adjusted R-Square. R
varies from 0.0 to 1.0, with 0 meaning no relationship (model is not
good) to 1.0, meaning the model perfectly describes the sample data.
An ANOVA is performed to determine the overall significance of the
model. If the ANOVA reveals a significant linear relationship, the
model may be a good representation of the sample data.
A plot of residuals from the fit is available. You may plot the fit
against any of the terms. Look for patterns in the residuals. If they
exist, a transformation of the data may make the fit more linear.
EXAMPLE: SIMPLE LINEAR REGRESSION
The following data (Fisher, 1976) are Homicide Rate and Handgun
Licenses Issued per 100,000 population for the years 1961 to 1973.
Simple Linear Regression Data
Year Homicide Handguns
Rate Registered
----------------------------------------
1961 08.60 178.15
1962 08.90 156.41
1963 08.52 198.02
1964 08.89 222.10
1965 13.07 301.92
1966 14.57 391.22
1967 21.36 665.56
1968 28.03 1131.21
1969 31.49 837.60
1970 37.39 794.90
1971 46.26 817.74
1972 47.24 583.17
1973 52.33 709.59
You only need a database with these numbers, and can exclude year.
___________________________________________________________
Please become a registered user - send in ORDER form.
23
KWIKSTAT 2.00
___________________________________________________________
Thus, create a database with two fields, HOMICIDES and HANDGUNS. The
data in the database will be from the table above, excluding the year
column. Thus, for the first record, the data would be 8.60 and 178.15.
The second record would be 8.9 and 146.41, and so on for 12 records.
To analyze this data choose regression module. You will be asked to
choose the independent variable (field) and a dependent variable. In
this case, the independent variable is the number of handguns
registered (usually the variable that is set or controlled), and the
dependent variable is homicides (usually the variable of observed
values that you may want to predict).
Pearson's correlation coefficient (rho) is reported (0.7263) as well
as R-squared (0.5275). Rho varies from -1.00 to 1.00. The further rho
is from 0.00, the stronger the correlation. A correlation of -1.00 or
1.00 is a perfect correlation. These are measures of how well the data
are correlated. The equation given is a mathematical representation
(model) of a straight (linear) line that passes through the data, and
can be used to predict the dependent variable given a value for the
independent variable. For example, in this case, if you wanted to
predict the homicide rate for 300 handguns registered, you would use
the equation:
Homicides = 4.910512 + 0.03761144 * 300 = 16.19
The t-test tests the statistical significance of the linear
relationship between the independent and dependent variable. A low
p-value (in this case 0.005) means that the two variable are
statistically significantly correlated for this data set. Reference a
text on regression for warnings about how to use (or not to use) this
kind of information for prediction purposes. In addition to these
results, you may also display a scatterplot of the data, and a
scatterplot of residuals. These plots are helpful to determine if a
linear fit to the data is appropriate.
EXAMPLE: MULTIPLE LINEAR REGRESSION
Longley introduced a data set which has often been used in comparing
multiple linear regression procedures in the literature. The database
used in the example is on the KWIKSTAT distribution disk. It is named
LONGLEY.DBF.
The Longley database consists of 7 fields, corresponding to the seven
columns of data in the above table. "Y" is the dependent variable (the
one to be predicted), and the other variables are independent
variables.
To analyze this data, choose the "Multiple Regression" option C from
the menu in the regression module. You will be asked to first enter
the independent variables. In this, these are fields 1 to 6, so you
enter "1,2,3,4,5,6" at the prompt. Enter "7" (TOTAL) as the dependent
variable.
___________________________________________________________
Please become a registered user - send in ORDER form.
24
KWIKSTAT 2.00
___________________________________________________________
A low p-value in the ANOVA suggests that the dependent variable TOTAL
is related to the independent variables. The first part of the
information tells you the intercept value and the coefficient values
for each of the independent variable. These can be used to create an
equation that represent the linear fit through the data. In this case,
the equation would be:
TOTAL = -3481930.1065 + DEFLATOR*15.0161517122 + GNP*-.03579443400 +
UNEMP*-2.0199053296 + ARMED*-1.0332049046 + POP*-.05130725587 +
TIME*1828.99249535
The t-value associated with each coefficient tests its significance in
the equation. In this case, you might question the validity of having
DEFLATOR, GNP and POP in the equation.
In choosing the variables to have in such an equation, you also need
to consider such questions as multicollinearity, heteroscedasticity
and parsimony. Refer to a good text on regression.
R-Square gives you a measure of the amount of variance explained by
the model, and the adjusted R-Square adjusts R-Square by how many
variables you have in the equation. The overall model is tested with
an analysis of variance. If the p-value for this test is low, it means
that the model (this particular selection of variables) provides a
good linear fit model for the set of data.
KWIKSTAT also provides an opportunity to examine residuals from the
fit. These residuals should look like a random scatter about 0. If
they do not, it may reveal a variable that is not a good linear
predictor, but may need to be replaced or transformed to provide a
better fit.
4) CROSSTABS, FREQUENCIES, CHI SQUARE
The "CROS" (KS20CROS.EXE) module performs analyses on categorical
data, that is, data observed in categories rather than measurement
data. Examples of categorical data are sex (Male, Female) and Color of
hair (Blonde, Black, Red, Brown). Some ordered data such as
socioeconomic status (measured as 1,2,3,4,5) is also analyzed like
categorical data.
Details on Specific Procedures
A) CHOOSE ANOTHER DATABASE
B) FREQUENCIES, PICTOGRAPH, PIE CHART: This procedure "counts" the
occurrence of each data value for a single variable or field. For
example, in the EXAMPLE database included on disk, there is a field
named "GROUP" which contains three categories, A, B, and C. KWIKSTAT
will count the occurrence of each category, and report that there are
11 "A's", 29 "B's" and 10 "C's". The program will prompt you to
___________________________________________________________
Please become a registered user - send in ORDER form.
25
KWIKSTAT 2.00
___________________________________________________________
Choose (A)nother analysis (P)rint (R)eturn to menu (D)raw P(I)e
Choose the Print option. Notice that in the printed table, the top
number for each group is the actual count from the database, and the
second number is the percent of the total. For example, 11 is 22% of
50.
After calculating the frequencies of a variable, you may display a
Pictograph (bar plot) or a Pie Chart. To select the Pictograph choose
the (D)raw option. To choose a Pie Chart, choose (I). You will be
asked to enter the name of the image to use (.IMG files will be
displayed). To display a bar plot, choose either BAR1 (a thin bar) or
BAR2 (a thick bar). Optionally, you may choose any of the other images
whose IMG files are displayed. See KWIKSTAT UTILITIES for information
on how to create your own images, or modify the images provided.
C) GOODNESS-OF-FIT: A goodness-of-fit test is a test that the
distribution of observed numbers closely matches the expected number
of occurrences. For example, suppose according to a genetic theory,
out of 250 peas crossbred, they should show a 9:3:3:1 ratio of Yellow
smooth, Yellow wrinkled, Green smooth, and Green wrinkled "offspring".
You would say that your null hypothesis (Ho:) was that you observed a
9:3:3:1 ratio of peas.
You would expect about (9/16) x 250 = 140.625 Yellow smooth peas, and
by similar calculations 46.875, 46.875, and 15.625 of the three other
varieties. After growing the plants, you observe 152 Yellow smooth,
39, 53, and 6 of the other three varieties.
The resulting analysis will give you a p-value of 0.031. Since it is
very small it suggests that the experiment DID NOT support the
theoretical ratio of 9:3:3:1. Thus, you would have evidence to reject
the null hypothesis. This example comes from ZAR (1974) page 46.
D) CROSSTABULATIONS, CHI-SQUARE:Crosstabulations look at two
categorical variables at once. A two-way table is constructed that
displays the number of counts for each pair of variables. KWIKSTAT
allows you to enter data for a two-way table from the keyboard or from
a database.
When you choose to enter the two-way table from the keyboard, KWIKSTAT
will ask you the size of the table (number of rows and columns). A
blank table will be presented on the screen, and you will then be
prompted to enter a number in each cell of the table. If you choose to
enter the information from the keyboard, KWIKSTAT will prompt you to
choose the two variables from the currently active database that you
wish to tabulate. KWIKSTAT will read the information from the
database, and construct the table.
The Chi-Square statistic tests the hypothesis that one variable is
independent of the other. A warning message that the Chi-Square test
___________________________________________________________
Please become a registered user - send in ORDER form.
26
KWIKSTAT 2.00
___________________________________________________________
may not be appropriate will be given if expected values in one or more
cells is less than 5. If the table is 2 x 2, Fisher's Exact test and
Chi-Square with Yates correction are given.
LIMITATIONS: Limits to tables being displayed on the screen are 10
columns by 7 rows. If the table is too big for the screen, only the
test results are displayed. Tables as large as 15 columns by 100 rows
may be printed on a line printer. More information is given on printed
tables.
E) 3-DIMENSIONAL BAR CHART: Data for the 3-Dimensional graph must be
entered first in option D, either from the keyboard or from a
database. When you choose the "3-D" option, you will be given a chance
to pick a title for the plot, and name the axes (or field names from
the database will be used).
For example, after entering the crosstabulation from the EXAMPLE
database (STATUS by GROUP), choose the 3-D option, and display the
graph. Once the plot has been displayed on the screen, you may want
view a slice of it at a time, ("D" option) to see any bars that may be
hidden from view. Pressing the Space Bar will reveal a menu at the
bottom of the screen.
EXAMPLE: 2 x 2 CONTINGENCY TABLE
A contingency table is a set of observations (counts) for two
classifications. Data for the example 2 x 2 table are observations of
the number of beetles and bugs on the upper and lower side of leaves.
(Zar, p 292) This data will be used for performing a Chi-square
analysis with and without Yates correction, as well as for Fisher's
Exact Test. It should be noted, that because one of the cells produces
an expected value less than 5, the KWIKSTAT produces a warning message
that a Chi-square analysis for this data set may not be valid.
2 x 2 Contingency Table Data
Beetles Bugs
-------------------
Upper Leaf | 12 | 7 |
-------------------
Lower Leaf | 2 | 8 |
-------------------
Using the "Crosstabs" option, you will be asked if the information for
the table will come from reading a database, or by you entering it
from the keyboard. Choose to enter data from the keyboard.
Next, you will be asked to specify the number of rows and columns. In
this case is is 2 rows and 2 columns. A blank table will appear on the
screen. Enter the numbers as in the table above by entering the number
12, press enter, enter the number 7, press enter, and so on. Once you
have entered all cells, the results of the analysis appear on the
___________________________________________________________
Please become a registered user - send in ORDER form.
27
KWIKSTAT 2.00
___________________________________________________________
screen. You may also choose to print the results to the printer.
If you choose the (P)rinter option, the information will be printed.
Crosstab Printout Explained
For each cell in a crosstab printout, 5 numbers are given. The top
number is the count that you entered. The second number is the
calculated expected value used to calculate the Chi-Square statistic.
The third through fifth numbers are percentages of the observed to the
TOTAL, ROW and COLUMN totals.
The statistics given include Chi-Square, Yates and the Fisher Exact
test. The p-value for each test gives you information about the
relationship between the two categories. If the p-value is low (say
p<=.05) then you have evidence to say that the two categories are not
independent. In this case it appears that beetles prefer the upper
sides of leaves and bugs are about split in their preference. In the
case of the Yates results, this decision is marginal.
There is a potential problem with this analysis since a normal rule of
thumb says that if an expected value is less than 5.0, the Chi-square
(and Yates) may not be valid. In this case, use the Fisher Exact test,
which suggests that the two categories are not independent, since the
Fisher p-value is 0.033.
EXAMPLE: ENTER DATA FROM A FILE
The previous example had you enter data from the keyboard, but you may
also read data from a file. Using the EXAMPLE.DBF dataset on the
KWIKSTAT distribution disks, you may create a table by choosing that
database, and choosing to create the database from a (D)atabase
instead of from the (K)eyboard. The way a database is set up to be
used to create a crosstabulation is by having field names that contain
a grouping code. For example, in the EXAMPLE database, the first few
records are:
A 12 22.3 25.3 28.2 30.6 5
A 11 22.8 27.5 33.3 35.8 5
B 12 22.8 30.0 32.8 31.0 4
The fist column is "GROUP" and the last column is "STATUS" GROUP has
values of A, B or C, and STATUS has values of 1, 2, 3, 4 or 5. The
cross-tabulation procedure counts the number of each value in each
chosen field, and uses this information to create the table.
5) SURVIVAL ANALYSIS AND LIFE TABLE
Module "LIFE" KS20LIFE.EXE performs Life Table and Survival Analysis
on a set of data. The data must be in the following form:
A TIME variable:This variable should contain a time variables (ie
___________________________________________________________
Please become a registered user - send in ORDER form.
28
KWIKSTAT 2.00
___________________________________________________________
minutes, days, years, etc) in which the subject or component has been
observed to be alive (not-failed).
A CENSOR variable:This variable must take on the values 0 or 1. A 1
means the subject has died (failed), and a 0 means the subject was
still alive (not-failed) at the last available time period.
Optionally, a GROUP variable:This variable may contain a grouping
variable (numeric or character) of up to 10 groups.
Once the data is entered into the program, a life table for each group
is produced which includes, for each time interval, the number
entered, withdrawn, lost, dead, exposed, proportion dead, surviving,
cumulative surviving, hazard and density.
A plot is given for the group or groups cumulative proportion
surviving. If more than one group is entered, a Mantel-Haenszel test
is performed to test the hypothesis of equal survival patterns for
each group.
A small version of the survival plot will appear on the screen, and if
you choose to print a report of the session the report will include a
larger version of the plot along with other information from the
analysis.
EXAMPLE: SURVIVAL ANALYSIS
Survival analysis is used to create life tables, to examine survival
trends over time, and to compare survival times between groups. A
database on the KWIKSTAT distribution disks named LIFE.DBF can be used
as an example. This data is from Prentice (1973). The first few
records in the LIFE.DBF database are:
72 1 1
411 1 1
228 1 1
11 1 1
25 0 1
144 1 1
8 1 1
The first column is the length of survival (TIME). The second column
is a censor indication. A 1 means that the subject has failed (died),
and a 0 means that the subject has not failed (still alive) at the
last period observed.
The third column contains a grouping variable. In this case it is
either 1 or 2. Group 1 may represent one treatment, while group 2
represents another kind of treatment. The object is to compute
survival curves to see if one treatment provides a longer average
survival distribution than the other.
After running a survival analysis, you will be asked if you want to
___________________________________________________________
Please become a registered user - send in ORDER form.
29
KWIKSTAT 2.00
___________________________________________________________
print the results to the printer. Life table and survival curve output
is illustrated on the next few pages. In this example, the
Mantel-Haenzel Chi-Square analysis produces a p-value of 0.397. This
indicates that the two distributions are not statistically
significantly different - thus neither treatment is superior in terms
of survival distributions.
KWIKSTAT UTILITIES
The KWIKSTAT UTILITY module allows you to setup your default disk
(path), select the kind of monitor you are using, select colors for
your display, print out data from the database and create images for
use in pictographs.
Specific Program Options
A) CHOOSE ANOTHER DATABASE
B) OUTPUT SDF FILE: You may output the data into a standard ASCII
TEXT file. (SDF file- Standard Data Format file). This is useful for
transferring your data to other programs. Along with the output of
data, you may also output a "format" file, which describes the
contents of the text file.
C) PRINT REPORT TO PRINTER OR FILE: You may output a listing of the
data in the dataset (or a selected subset of the database). In this
procedure you may specify the following report features:
WHICH DATA FIELDS TO OUTPUT
OUTPUT RECORD NUMBER AS A COLUMN
TITLE
NUMBER OF LINES PER PAGE
WIDTH OF PAGE (default is 80)
OUTPUT TO A FILE OR PRINTER
OUTPUT A SUBSET OF THE DATA (Search)
NOTE:You may want to place a coded variable in your data set which
will allow you to easily select a subset of data to output. Subset
searches can be
1) Exact: case is ignored
2) First one or more letters in a field: (AL* matches ALLEN,
ALBERT, etc)
3) Keyword: match a letter pattern within a field (ie [AL] matches
ALLEN, BALES, etc).
The REPORT procedure is menu driven. Simply answer the questions as
you are prompted. If the report is too wide to fit on a single width
of the specified paper width, the report will be printed in parts.
___________________________________________________________
Please become a registered user - send in ORDER form.
30
KWIKSTAT 2.00
___________________________________________________________
D) SETUP KSTAT.INI - MONITORS, COLORS, PATH: This option allows you to
tell KWIKSTAT information about the kind of monitor you are using and
where you data is stored.
You will be asked to select between color-type monitors (CGA, EGA,
PGA, VGA, etc) and Monochrome Graphics (Hercules) Monitors. Standard
IBM Monochrome monitors without Hercules-type cards will NOT display
graphics. All KWIKSTAT graphics are produced in CGA modes. However,
standard EGA, VGA and other color monitors will emulate the CGA mode
without problem. There are a few clone color monitors that may not be
able to support CGA graphics; however, they are usually able to
support monochrome graphics.
After you choose monitor type, you will be presented with several
color/highlight options. Choose the one you like from the list. The
PATH question has to do with where your KWIKSTAT data will be stored.
If you have installed KWIKSTAT on the C: drive in the \KWIKSTAT
directory and you want all of your databases stored in this directory,
your path would be C:\KWIKSTAT. If all of your database are stored in
your dBASE III directory, which is on the C: drive in the directory
\DB3, your path would be C:\DB3. If you are storing all of your data
on a disk in the B: drive, your path would be B: or B:\ You may change
these options at any time..
E) IMAGE CREATION/EDITING: The image program allows you to create new
IMG files or edit images already created. When you begin the IMAGE
module, you will be asked if you want to create a NEW image, or to
edit an OLD image. If you choose to enter a NEW image, you will be
asked the pixel size. Maximum size for an image is 40 pixels (dots)
wide and 30 pixels high. For example, you may create an image 30 by 20
pixels. The Pictograph routine will adjust its graph according to the
size of the image.
In the image editor, you may move the cursor around the grid, and
select to fill a dot by pressing the numbers 1, 2 or 3. To unfill a
dot, place the cursor at the dot and press the space bar or 0. You
will see a version of the image in its correct size at the upper right
corner of the screen. Once you have created or edited an image, choose
the (S)ave option to write the information to disk. Names for image
files are 1 to 8 characters in length. Do not use an extension when
giving a name, the extension IMG is always assumed.
___________________________________________________________
Please become a registered user - send in ORDER form.
31
KWIKSTAT 2.00
___________________________________________________________
APPENDIX I
SAMPLE DATA SETS ON DISK
EXAMPLE.DBF contains the fields GROUP, AGE, TIME1, TIME2, TIME3,
TIME4, and STATUS. Data can be used to illustrate Repeated Measures
(Use TIME variables), or Independent group ANOVA (Use GROUP as
grouping factor). It can be used for Crosstabulation (Use GROUP and
STATUS).
EX.DAT is the raw data, from which a database like EXAMPLE.DBF could
be created using the DATA module. In the DATA module, create a new
database, with the following fields, then enter the data with the
Enter from a file option. The format for the EX.DAT file is:
FIELD TYPE WIDTH DECIMALS
----- ----- ------- --------
GROUP CHAR 1 -
AGE NUM 4 0
TIME1 NUM 5 1
TIME2 NUM 5 1
TIME3 NUM 5 1
TIME4 NUM 5 1
STATUS NUM 2 0
LIFE.DBF - Database for the LIFE module. It is used in an example
for the LIFE module.
LONGLEY.DBF - Data from Longley (1946). This data is used in the
Multiple Regression Procedure example. The variable TOTAL is the
dependent variable and the rest are independent variables.
___________________________________________________________
Please become a registered user - send in ORDER form.
32
KWIKSTAT 2.00
___________________________________________________________
APPENDIX II
SOME COMMON ERROR CODES
24 - Device Timeout - Your printer may be off or disconnected.
25 - Printer has malfunctioned
27 - Printer is out of paper
61 - Disk Full
67 - Too many files on one diskette
70 - Disk is write protected
71 - Disk is not ready (Is drive door closed?)
72 - Disk Media Error (Disk may be bad)
Others: Check Appendix in BASIC manual
___________________________________________________________
Please become a registered user - send in ORDER form.
33
KWIKSTAT 2.00
___________________________________________________________
APPENDIX III
USER'S BALLOT
Please indicate your preference for improvements in KWIKSTAT. On
a scale of 0 to 10
0 = Very Low priority for this change
10 = Very High priority for this change
Vote Proposed item of change
---------------------------------------------------
____ More "BY GROUP" capabilities
____ Ability to sort database
____ Add multi-way ANOVA
____ Add more Non-parametric statistical tests
____ Add General Linear Model
____ Make Report more flexible
____ Add stem and leaf plot
____ Add time series analysis
____ Speed up calculations
____ Add more graphics
____ _____________________________________________
____ _____________________________________________
____ _____________________________________________
____ _____________________________________________
Mail to:TexaSoft, P.O. Box 1169, Cedar Hill, Texas 75104.
Thanks.
___________________________________________________________
Please become a registered user - send in ORDER form.
34
KWIKSTAT 2.00
___________________________________________________________
APPENDIX IV
Bug Report for KWIKSTAT
--------------------------------------------------------------
Please explain in detail the problem that occurred. If possible,
send a print out of the results or Print Screen.
KWIKSTAT VERSION YOU ARE USING:________________________
KWIKSTAT MODULE where problem occurred:____________________
YOUR COMPUTER: BRAND/Model_____________________________
MONITOR TYPE:________AMOUNT OF MEMORY:_______________
VERSION OF DOS YOU ARE USING:____________________________
MEMORY RESIDENT PROGRAMS YOU USE:____________________
PROBLEM:
---------------------------------------------------------------
Mail to:TexaSoft, P.O. Box 1169, Cedar Hill, Texas 75104. Thanks.
___________________________________________________________
Please become a registered user - send in ORDER form.
35
KWIKSTAT 2.00
___________________________________________________________
APPENDIX V
Hercules - Monochrome Graphics Monitors
Hercules graphics allow standard monochrome monitors to display
graphics. In order for KWIKSTAT to know that you are using a
Hercules monitor, you must do the following:
1) Enter the command QBHERC before entering KWIKSTAT. You can put
this command in the KS.BAT file as illustrated below.
2) In the UTILITIES module, choose the SET-UP option and tell
KWIKSTAT that you are using a Hercules monitor. Choose the
save-to-disk option.
3) If your particular Hercules setup does not support printing to
your printer, you may have to acquire a supplemental program to
allow you to print graphics screens to the printer.
EXAMPLE BATCH FILES: These two batch files show how you
might implement special printer and monitor programs into
the KS.BAT batch file. The first uses the command LASERJET
to invoke a program for Laserjet printer support. The
second batch file uses the QBHERC command to allow KWIKSTAT
to use graphics on a Hercules type monitor, and the command
SCRNDMP invokes a program that allows a printscreen of
Hercules type graphics to be printed on a dot matrix
printer.
LASERJET A QBHERC
KS20DATA SCRNDMP
KS20DATA
Printers
In order to be able to print graphics screens from KWIKSTAT, you must
have a printer that supports graphic printing, and you must have a
program that will drive the printer. For most common dot-matrix
printers, the program called GRAPHIC.COM, which comes with PC-DOS is
sufficient. However, with other printers, such as laser printers, you
may have to acquire a special printer driver.
For the H-P Laserjet, there is a program you may acquire from
shareware and public domain sources. It is called LASERJET, and allows
you to print graphic screens to your Laserjet printer. For Hercules
graphics users with dot matrix printers, the program SCRNDMP usually
allows your to print graphics. Refer to the sample batch files on the
previous page to see how to place your printer support program into
your KS.BAT file so that it will be invoked each time you begin
KWIKSTAT. A sampling of printer support programs are on Disk 2.
TexaSoft also can provide a disk with additional printer support
programs. See the order form on disk for more information about the
___________________________________________________________
Please become a registered user - send in ORDER form.
36
KWIKSTAT 2.00
___________________________________________________________
cost of this disk.
References
Dixon, W.J., and Massey, F.J., INTRODUCTION TO STATISTICAL ANALYSIS,
McGraw-Hill Book Company, New York, 1969.
Gunst, R.F. and Mason R.L., REGRESSION ANALYSIS AND ITS APPLICATIONS,
MArcel Dekker Inc, New York, 1980.
Longley, J.W. "An appraisal of least squares programs for the
electronic computer from the point of view of the user." JASA, 1967,
62, 819-831
Neter, J. and Wasserman, W., APPLIED LINEAR STATISTICAL MODELS,
Richard D. Irwin, Inc, 1974.
Prentice, R. L. "Exponential survivals with censoring and explanatory
variables. BIOMETRIKA 60, 1973, 279-288.
Tukey, J.W., EXPLORATORY DATA ANALYSIS, Prentice Hall.
Winer, B.J., STATISTICAL PRINCIPLES IN EXPERIMENTAL DESIGN, Second
Edition, McGraw-Hill Book Company, 1971.
Zar, J.H., BIOSTATISTICAL ANALYSIS, Prentice Hall. Inc, 1974
Products mentioned: Lotus 1-2-3 is a product of Lotus development,
dBASE III is a product of Ashton-Tate.
___________________________________________________________
Please become a registered user - send in ORDER form.
37
KWIKSTAT 2.00
___________________________________________________________
KWIKSTAT PROGRAM LIMITS:
KWIKSTAT DATABASE: 128 Variables 10 characters to a name 60 character
maximum width for character variable
DESCRIPTIVE STATISTICS: Detailed Statistics on a single variable:
5,000 cases maximum. Summary statistics: No maximum. Histogram: 5000
cases maximum Scatterplot and Time Series plot: 3,000 cases maximum.
T-TESTS AND ANOVA: 10 groups maximum, 4,000 cases.
REGRESSION: Simple linear: 2,000 cases maximum Multiple:10 independent
variables, 300 cases.
CROSSTABS: 15 by 100 table to printer, 7 by 10 to screen.
SURVIVAL ANALYSIS: 10 groups, 1,000 cases
38
