Search code examples
spsschi-squaredcontingency

Entering contingency table in SPSS


I have a contingency table of the form:

            # successful    # unsuccessful  Totals
Amateurs    14              1544            1558
Experts     7               17              24

I'm having trouble getting this data into SPSS v21 so I can analyze it (chi square). I've tried directly inputting the data like this and using Analyze> Descriptive Statistics>Crosstabs, but the analysis results are incorrect that way, separating them into strange categories and giving me a chi square value of 2. When I do the calculation by hand I get 144.2. If anyone has input as to how to get this correctly entered, I'd greatly appreciate it. Thanks!


Solution

  • In this case you have two dichotomous variables: status (amateur/prof) and succes (succes/unsuccess). So there are (2*2=) four possible response patterns. Create one observation for each pattern and fill in its frequency in a separate variable. Then weight by this variable. Now each single record 'counts for' N records where N is the value on the frequency variable.

    I'd probably code your example as follows:

    data list free/status success freq.
    begin data
    0 0 1544
    0 1 14
    1 0 17
    1 1 7
    end data.
    
    weight by freq.
    
    value labels status 0 'Amateur' 1 'Professional' / success 0 'Failure' 1 'Success'.
    
    set onumbers labels.
    
    crosstabs status by success
    /statistics chisquare.