I have a two level structure, items within persons. There are five items,
each measured on a five-point Likert Scale (responses are 1,2,3,4,5). I
need to create a scale for each person based on the five items using IRT
instead of the simple average of items in order to make use of all of the
data. How would I go about this? I can first reshape the data, but where
do I go from there?
For example, my data may look like this originally:
person item1 item2 item3 item4 item5
1 3 2 3 4 5
2 5 4 2 4 3
3 3 2 1 2 2
I can reshape the data into:
person item scale
1 1 3
1 2 2
1 3 3
1 4 4
1 5 5
2 1 5
2 2 4
2 3 2
2 4 4
2 5 3
etc.
What commands might I use to create one scale for each person using IRT
based on the responses to the 5 items?
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