Title: Principle in Evaluating the Test

Learning Outcome: Can establish the validity of the test by conducting an item analysis.

Learning Objectives: (1) Determine the index of difficulty and index of discrimination (2) Make a decision about the test items whether it will be retained, revised and discard.

Content Exploration:

In a general achievement test with an individual item which is 50 percent difficulty is better. Items of 100 percent or zero (0) percent answered by students are valueless in a test of general statement and should be revised.

The validity of the individual item is determined by the index of discrimination.

A common practice is to arrange the test papers from highest to the lowest score.

One-third of the papers from the highest or upper group be compared with one-third of the papers from the lowest group of the same item.

Set aside the middle group. For instance, there are 45 test papers, one-third of 45 is

15. And the first 15 belong to the upper group while the last 15 belong to the lower group. Estimate the index of discrimination and index of difficulty by using the formula:

\f\f\f\f\f\f\f\f