home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Magnum One
/
Magnum One (Mid-American Digital) (Disc Manufacturing).iso
/
d13
/
stistics.arc
/
LONG-T.DOC
< prev
next >
Wrap
Text File
|
1988-07-24
|
3KB
|
53 lines
LONG-T (Student's T-test, long version)
AIM: This is the standard T-test, used to compare sample means between two
groups with any number in each group. This is a highly useful program, and
it is unique in that two different tests are applied. That is, if the
variances of the two groups are equal (as tested by the F-ratio), a
standard T-test formula is applied. If the variances are unequal, a
special formula for the T-test is applied.
Input of data can be from the keyboard, or from a data file created in the
NON-DOCUMENT mode of WordStar, as shown below. Input from the keyboard is
also described below. For either keyboard or datafile input, the user is
first asked if the results are to be sent to the screen only, or both the
screen and printer. If printer output is selected, the user has the option
of having just the results, or both the results AND the raw data printed.
Next, a title for your run is input (date, animal identification data,
etc.). Following this, the user is asked for the N in group 1. Data for
group 1 is then entered. When the last item in group 1 is entered, an N
for group 2 is asked for, followed by the input of group 2 data.
EXAMPLE: Two groups of embryos were measured for crown-rump length
(millimeters). One group had been given a teratogen; the others were
normal controls. The sample output on the back of this sheet shows the
individual numbers for the two groups (ten embryos in each group).
Note that the program gives a calculated T-value, an exact P-value, and
statements concerning significance (or lack of it) at both the 95 and 99%
levels.
SAMPLE FORMAT FOR DATA FILE <== Title, up to 65 characters of any kind.
5 <== N1
2.032 <== X value 1
1.5 <== X value 2
1.6 <== .
1.95 <== .
1.99 <== X value N1
5 <== N2
3.124 <== Y value 1
1.217 <== Y value 2
0.984 <== .
1.5 <== .
1.4 <== Y value N2
REFERENCE: Mather, K. 1951 Statistical Analysis in Biology. Methuen
and Company, Ltd., London. Page 56-57.
FORTRAN VERSION: Dr. Stanley Kaplan May 65
BASIC VERSION: Dr. Stanley Kaplan Jul 81
PASCAL VERSION: Dr. Stanley Kaplan Sep 85
UPDATES: Oct 86 (Version 2.00)
Feb 87 (Version 2.10)
Feb 88 (MS-DOS, Version 2.2)