4. Evaluation of measuring tools: item analysis. Psychometrics . 2011/12. Group A ( English ). Introduction.
Psychometrics. 2011/12. Group A (English)
A: number of subjects who hits the item.
N: number of subjects that attempt to respond the item.
Calculate ID and Idc to ecah item
Items which have suffered a major correction are those that have proved more difficult.
Ho: means in both groups are equal.