Hi! I weighted 1 case and then performed Compare Mean with other groups of variables in spss, but the N (number of cases) is increased, which is greater than the unweighted compare mean's N and the numbers are over the total cases we have, why this happened, and how can I figure it out? thank you.
Hello Yy,
In SPSS, using the weight cases command causes the program to treat a case as being replicated k times, where k is the value of the weighting variable chosen. So, it is as if your data set has been changed by adding (k - 1) additional instances of a given case, each having the same data points as the original case.
So, yes, the apparent N can exceed the number of non-missing cases (usually, rows) in the data set when you use the weight cases option.
Good luck with your work.
David Morse has given you a good summary of what the WEIGHT command does. For more info, Read The Fine Manual:
- https://www.ibm.com/docs/en/spss-statistics/beta?topic=weight-overview-command
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