Monster Media 1994 #2

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Text File | 1994-07-01 | 14KB | 366 lines

KWIKSTAT Program Help Screens @1,How to Enter Data:Keyboard, or from dBASE III file @3,How to Use data from a dBASE III file @4,Setup of the default file path @5,Utilities Module, Reports, Import from 1-2-3 @6,Descriptive Statistics @7,t-test and ANOVA, paired or independent groups @9,Non-Parametric Comparisons @10,Simple Linear Regression and Multiple Regression @11,Correlation @12,Using the Kwikstat Viewer @13,Using REPLACE & using functions in REPLACE and SUBSET ##1 ##DATA KWIKSTAT -------- HOW TO ENTER DATA Data may be entered from the keyboard, or from an ASCII text file. Data already stored in a dBASE III or IV file may also be used. ENTERING DATA FROM THE KEYBOARD 1. CREATE THE STRUCTURE OF YOUR DATABASE by selecting the "CREATE" option in the DATA menu. 2. ENTER DATA by choosing the Enter Data option on the DATA menu. 3. EDIT DATA by choosing the EDIT option on the DATA menu. 4. CREATE NEW VARIABLES by choosing the TRANSFORM option, or choose the FIELD (F9) option in entry mode. ##2 ENTERING DATA FROM AN ASCII TEXT FILE Create a database structure using CREATE. Structure should match the columns of data in the data file. For example, your data is in a file named "MYDATA.TXT". A database structure could be created using the following format: Field Type Width Dec NAME C 10 AGE N 2 0 BDATE D 8 ^ ^ ^ ^ │ │ │ └─────────────Number of decimals in numeric data │ │ └───────────────────Columns where data is found │ └─────────────────────────Data type └────────────────────────────────Variable (field) name This means NAME is in columns 1-10, AGE in 11-12 and BDATE in 13-21. NOTICE:The format MUST be inclusive of all columns. DO NOT SKIP COLUMNS when specifying where data is located. ##3 ENTERING DATA FROM A DBASE III or VI FILE KWIKSTAT reads data directly from dBASE III and IV files. In each module, you may specify which dBASE file to use. The module will display all ".DBF" files in the default path by listing them in a pick box. To choose the database to use, press the up or down arrow keys to highlight the name of a database, then press Enter. You may also call files from other directories by pressing the F2 key when the database list appears. Specify another path for the program to search, enter \DB3. A new pick list appears listing .DBF files in the specified path. ##4 ##SETUP SET UP DEFAULT DISK PATH OR DISK DRIVE In the Main KWIKSTAT module, select the CHANGE SETUP OPTIONS on the HELPS menu to set up the default disk drive or path, select monitor colors, printer and other criteria. When asked to enter the default directory, just press Enter without entering any specification if the data is stored in the same drive as the program (the default directory). Otherwise, you can specify another subdirectory, such as "MYDIR". To do this, enter \MYDIR\ or C:\MYDIR\ To use the B: drive as the default directory, enter the specification B:\ (A MUST FOR 2-DISK SYSTEM USE!) ##5 ##UTIL KWIKSTAT UTILITY MODULE KWIKSTAT allows you to input and output data in the UTILITY Module. o Output a listing of the data in the dataset (or a selected subset of the database). Allows you to view the report before printing it. o Output the data into a standard ASCII TEXT (SDF) file. Useful for transferring the data to other programs. o Import data from 1-2-3 WKS, WK1 files. For WK* import, you need to know the range in the spreadsheet, such as A1..D15. o Import from comma delimited files, where data is in the form: 23,34,"label",11 NOTE: Once you have imported, you can change field name, width, etc by using the Modify option on the DATA menu. ##6 ##STAT DESCRIPTIVE STATISTICS In the STATISTICS module, examine summary statistics. DETAILED STATISTICS - gives mean, standard deviation, etc, plus percentiles, confidence interval and a box plot on one variable at a time. SUMMARY STATISTICS - gives mean, st. dev. etc. on several variables at a time, and allows listing of statistics by a grouping factor. P-VALUE - calculates p-value for Z, t, Chi-Square and F statistics HISTOGRAM - examine the distribution of a continuous variable SCATTERPLOT - examine the relationship between two variables TIME-SERIES - examine pattern of a single variable across time -- data should be ordered STEM and LEAF Display - summarizes data using a table/graph ##7 ##TTEST T-TESTS AND ANOVA'S FOR INDEPENDENT GROUPS OR SINGLE GROUP -------------------------------------- TWO GROUPS:Student's t-test, data expected to have a grouping variable, also provides a test for the equality of variance, and two versions of the t-test according to whether the variances can be considered equal. 3 TO 10 GROUPS: One way ANOVA, Newman-Keuls multiple comparisons performed, data must have a grouping variable. Comparative box plots displayed. T-TEST AND ANOVA from summary data - no box plots. Single sample t-test - you choose the hypothesized value to test. ##8 ##REPEAT T-TESTS AND ANOVA'S FOR PAIRED OR REPEATED MEASURES ------------------------------- TWO TIME PERIODS OR TWO PAIRED OBSERVATIONS:Students t-test for paired observations. Data is expected to be paired within each record in the database. For example: two fields in the database could be: Before After 200 175 130 123 etc. 3 TO 10 REPEATED MEASURES: An extension of the t-test, with 3 or more repeated measures. Repeated Measures ANOVA performed, with Newman-Keuls multiple comparisons. Comparative box plots displayed. ##9 ##NPAR NON-PARAMETRIC COMPARISONS Note:Use non-parametric procedures when the data cannot be assumed to be normally distributed. FOR INDEPENDENT GROUPS OR SINGLE GROUP -------------------------------------- TWO GROUPS: Mann-Whitney U, comparison based on ranks of the data. 3 TO 10 GROUPS: Kruskal-Wallis One-way ANOVA based on ranks, Newman-Keuls multiple comparisons performed at the 0.05 significance level. FOR PAIRED OR REPEATED MEASURES ------------------------------- TWO TIME PERIODS OR TWO PAIRED OBSERVATIONS: Friedman's Test. 3 TO 10 REPEATED MEASURES: Friedman's ANOVA with Newman-Keuls multiple comparisons. ##10 ##REG LINEAR REGRESSION SIMPLE LINEAR REGRESSION - relating two variables. This procedure provides an equation representing a straight line fitted through the data, and a test of the significance of the linear relationship. You can also plot the data to verify a linear trend and to examine residuals. MULTIPLE REGRESSION - Allows you to relate up to 10 independent variables to a dependent variable. The significance of each variable is determined, and the coefficients to a prediction are calculated. You can use the information on the significance of each variable to determine what variables to leave in the equation and which to remove in order to find the best equation possible. ##11 ##REG CORRELATION PROCEDURES CORRECTION calculates the Pearson and Spearman correlation coefficient for a pair of variables. The significance of the coefficient is also given. Usually, Pearson's is calculated when the data are normal, and Spearman (which is based on ranks) is used for non-normal data. MATRIX OF CORRELATIONS - allows you to calculate combinations of correlations (Pearson) on up to ten variables at a time. DISPLAY A MATRIX OF SCATTERGRAMS - allows you to visually examine the relationship on pairs of data for up to 10 combinations at a time. ##12 ##VIEW Using the Kwikstat Viewer The Kwikstat viewer allows you to examine output from an analysis that could be too big to appear on one screen. When the viewer appears, you can move around the displayed results by pressing the arrow keys, PgUp, PgDn, Home and End. If you are using a mouse, you can use the scroll bars on the right side and bottom to position the output on the screen. The function key commands available in the viewer are described below. To activate one of these commands, press the function key or click the option on the button bar at the bottom of the screen: F1 - Display this help screen. F3 - Send setup code to printer (for condensed print, etc.) F5 - Goto a line in the output (Press F5, then enter a line number.) F7 - Exit the viewer. F8 - Define size of margin for output. F9 - Define a title to be used on output. F10 - Output the contents of the viewed file to a printer or file. When you choose this option, the default output is the port you specified in the program setup (i.e., LPT1: meaning line printer port 1). You can press Enter to accept this default, or type a file name to save the contents to a file. ##13 ##REPLACE ##SUBSET Using Functions & Expressions in the REPLACE and SUBSET Options --------------------------------------------------------------- "REPLACE WITH" FIELD (in Replace option): Use either a math expression or a database expression. CONDITION FIELD (in Replace and Subset) : Use only a database expression. A database expression allows many mathematical and character expressions, as described below. The math expression is provided for performing calculations using scientific mathematical functions. In the REPLACE WITH field, the default expression type is the database type. In order for an expression to be evaluated as a strictly math expression, you must place an equal sign "=" at the beginning of the expression. For example, if you want to perform the calculation WEIGHT/HEIGHT, you can enter the expression as-is in the REPLACE WITH field. (continues...) ##14 (REPLACE & SUBSET continued) However, if you want to calculate the log of WEIGHT/HEIGHT, you must enter the expression as =LOG(WEIGHT/HEIGHT) since the LOG function is not supported as a database expression function. The equal sign signals to the program to use the math calculator. The information below outlines the capabilities of both expression types. Mathematical operators: Add + Subtract - Divide / Multiply * Exponentiation ^ (Math calculator only) For Character fields, the database calculator supports the operation: Add + (appends one string to another) (continues...) ##15 (REPLACE & SUBSET continued) Following are a few examples of correct expressions: AGE/HEIGHT =SCORE^2 (= signals math calculator) LTRIM(FIRST)+' '+LAST Note: Literal strings included in expressions must be surrounded by single quotes. For example, 'Hello' is a literal string. Character field names are used without quotes. For example, NAME is a field name. A correct string expression using these two strings would be: 'Hello '+NAME TIP:Only if you use a numeric operation or function not supported by the database calculator will you need to place an equal (=) sign at the first of the expression. For a list of the functions supported, refer to Chapter 2 in the manual. (continues...) ##16 (REPLACE & SUBSET continued) Following are some example uses of functions in REPLACE or SUBSET: ASC - Converts the first character of a string to its ASCII code. For example, the function ASC('A') would return the value 65, since 65 is the code for an uppercase A. AT - Returns the starting position of one character string within another character string. For example, the expression AT('Bill', 'Wild Bill') = 5 since the string 'Bill' begins five characters deep in the string 'Wild Bill'. CALENDAR and JULIAN - The JULIAN function converts a date into a number, where 1 is January 1, 1583. CALENDAR converts a julian number into a Date. You can convert dates into numbers, then find the number of days between dates by subtraction. CAPS - Converts the first letter of each word into a capital. For example, CAPS('this is a test') would become 'This Is A Test'. (continues...) ##17 (REPLACE & SUBSET continued) CHR - Converts a number into its ASCII value. For example, CHR(65) is equal to the character string 'A'. DELETED - Returns a T if the current record is marked for delete, else it returns a F. Can be used to conditionally replace a value depending on if the record is deleted or not. IIF - Selects between two expressions. The syntax is IIF(logicalexpression, expression1, expression2). The logical expression is either T or F. If the logical expression is T, then returned value of this function is expression1, else the returned value is expression2. INT - Rounds down to nearest integer. INT(3.2) is equal to 3. LEFT and RIGHT - Returns the left or right portion of a string. For example, LEFT('Wild Bill',3) would return the string 'Wil' and RIGHT('Wild Bill',3) would return the string 'ill'. (continues...) ##18 (REPLACE & SUBSET continued) LOWER and UPPER - Returns lower or upper case string. For example, LOWER('Wild Bill') would return 'WILD BILL'. LTRIM, RTRIM and TRIM - Trims blanks from right, left or both ends of a string. For example, LTRIM('Wild Bill ') would return 'Wild Bill'. If the field FIRST contained the string 'Mark ' (6 blanks on the end) and the field LAST contained 'Walker ' (7 blanks on the end), the expression FIRST+LAST would be 'Mark Walker '. To obtain the string 'Mark Walker' you would use RTRIM(FIRST)+' '+RTRIM(LAST). SUBSTR - Extracts a string from the middle of a string. For example, SUBSTR('Wild Bill',3,4) would be 'd Bi', which begins with the 3rd character in the initial string, and is 4 characters long. If the 4 were left off, the result would be 'd Bill' -- which is the remainder of the string starting with the 3rd character. VAL - Returns the value of a string. For example VAL('24') is the number 24.