ITEMS — Analysis of categorial items: frequencies and weights

This program evaluates syndrome check lists on the item level in order to reveal characteristic patterns that may be present in subgroups of a given sample of cases. Subgroups are defined through a special variable that is to be created in a problem-dpendent way. Optional frequency charts may be used to visually identify group-specific patterns as well as unspecific patterns, that is, patterns that show up in all subgroups under comparison.

            Specificationlist:       ITEMS
            ------------------------------
            I4 NVAR              Undefined
            I4 NOBS                      0  Default-value
            I4 LGIN                     50  Default-value
            I4 MISS                   -999  Default-value
            I4 ICUT                      1  Default-value
            I4 PROT                      0  Default-value
            I4 PLOT                      0  Default-value
            I4 LPRT                      6  Default-value
               FORM(Format)
 
            01 NVAR Number of variables to be processed
            02 NOBS Maximum number of observations
            03 LGIN Logical unit number of input-device
            04 MISS Specifies how missing data are coded
            05 ICUT Controls whether case is affected/unaffected
            06 PROT Controls output to display/printer
            07 PLOT Controls output to plotter
            08 LPRT Logical unit number of output-device
            09 FORM Optional format-string for data input
            10 DEMO Examples that illustrate program function
 
            - NVAR:     Number of variables to be processed (maximum 100)
 
            - NOBS:     Maximum number of observations
 
            - LGIN:     Logical unit number of input-device (standard=40;
                        valid numbers are 40-98)
 
            - MISS = m: Items with values "m" are treated as missing data
 
            - ICUT = p: Defines cutoff between affected and unaffected
                        individuals: individuals with values < "p" are
                        treated as unaffected
 
            - PROT = 0: No print output
                   = 1: List of empirical frequencies without variable labels
                   = 2: List of empirical frequencies with variable labels
 
            - PLOT = 0: No plot output
                   = 1: Frequency charts on plotter (postscript)
 
            - LPRT:     Logical unit number of plot-device (standard=6;
                        valid numbers are 40-98)
 
            - FORM:     Optional format-string for data input (I-format):
                        must be of FORTRAN-like form: FORM(format-string)
 
 
            - DEMO: Empirical frequencies of alcohol items in males/females
 
           

Example

 
            &&START DBANK
            &&START LABEL=COGA alcohol items
             NLAB=37,LGIN=70,MODE=1,PROT=1
             FORM(T9,A8,1X,A40)
            &&START ITEMS=COGA empirical frequencies of alcohol items
             LGIN=71,NOBS=9000,NVAR=37,MISS=-9,ICUT=1,PROT=2,LPRT=72
             FORM(T7,37I2)