Skip to main content

Table 4 Linear Regression Analysis of Item Performance as a function of Item Characteristics

From: Evaluation of the effect of items’ format and type on psychometric properties of sixth year pharmacy students clinical clerkship assessment items

Predictor*Difficulty IndexDiscrimination IndexPoint biserial
Coefficientp-valueCoefficientp-valueCoefficientp-value
Model 1$#F(2,170) = .78.46F(2,170) = 6.84.001F(2,170) = 15.192<.001
Case/Noncase based items−.04.26.08.019.01.67
Open-ended (essay)/MCQs items−.01.89−.10.001−.14<.001
Model 2@#F(2,72) = .76.47F(2,72) = .40.67F(2,72) = .18.83
Case/Noncase based items−.02.77.04.39−.01.79
Number of Choices−.03.23.01.78.01.60
  1. *because the number of choices variable can’t be included in the same model as the item type variable, two separate models (one for item format and item type and then one for item format and number of choices among the MCQ questions) were analyzed
  2. $N = 173
  3. @N = 75
  4. #The interaction of the two factors in the model was tested and no significant effect was detected with also no effect on the significance on other factors