Test Item Analysis and Relationship Between Difficulty Level and Discrimination Index of Test Items in an Achievement Test in Biology

Current piece of work is focussed on the analysis of test items constructed in the subject of Biology for class IX. It involved the analysis of difficulty level and discrimination power of each test item. There were 120 objective type questions in the achievement test and was administered on a sample of 500 students from government and private schools. The findings of the work showed that most of the test items fall in the acceptable range of difficulty index and discrimination index. However, nine of the test items were rejected due to very high or very low difficulty level and poor discrimination power. Using the findings relationship between the difficulty index of each item and the corresponding discrimination index is carried out using Pearson correlation formula. Instead of a linear relation, it was found that item discrimination power increased with the increase in difficulty value but got decreased for very easy and very difficult test items. This work is significant for the researchers and school teachers in framing test items with optimum difficulty and discrimination power.