search for: righta_a

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2006 Apr 13
1
Subset rows over multiple columns
...in the data below the value R0000160 is found in the first and second columns (itd_1 and itd_45). These data are student responses to multiple choice test items from a computer adaptive test. So, the variable itd_1 denotes that item i was presented to student k in position t and then the variable righta_a and righta_b denotes a correct (1) or incorrect response to that item when it was presented. My goal is to get the p-value (mean of the binary variable) for each item irrespective of when it was presented to the student. So, in the sample case below, I would use all elements in righta_a (except f...