• At the end of the semester, the students will be able to know the following: The procedures in Item Analysis Computation for the Index of Difficulty and Index of Discrimination Interpreting the Test Scores
• 3 Criteria Determining the Desirability of an Item:• 1. Difficulty of an Item. ( How difficult the item is.)• 2. Discriminating power of an item (+/-)• *positive disc= Pu > PL• 3. Measure of Attractiveness (+/-)• (Determines how attractive is the distractor)• *keyed response=correct answer• *wrong options= distractor• *effective distracters= more students in lower group chose it than the upper group.
2.Arrange the scores from highest to lowest.3.Separate the top 27% and the bottom 27%4.Find the proportion of each score. (frequency/the 27%)Then solve for this:*Index of Difficulty: *Index of Discrimination: Df= (Pu+PL)/2 Ds= Pu-PL*Measure of Attractiveness *where: Da= Pu-PL/St Pu= upper class PL=lower class St= number of students
• Discriminating Index• .40-up= very good item(accept)• .30-.29= reasonably good item but subject for revision• .20-.29= marginal item (revise)• Below-.19= poor item (reject)• Range of Difficulty• 0.00-0.20 – Very difficult• 0.21-0.40 – Difficult• 0.41-0.60 – Moderately difficult• 0.61-0.80 – Easy• 0.81-1.00 – Very easy