[Rasch] What is the relationship between number of items and the number of participants needed?
mike at winsteps.com
Wed Jun 19 09:13:12 EST 2013
You asked: "What is the relationship between number of items and the
number of participants needed?"
Here are a few guidelines to launch our discussion:
1) at least 30 observations of each item and of each person, if possible.
2) at least 10 observations of each score-level on each rating scale.
3) since we are usually more concerned about item fit than person fit,
there must be more persons than items.
Folks, please tell us about your own guidelines ....
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