Using the information provided in the â€œItem Analysis T-e-s-t Questionsâ€ pdf file, calculate the difficulty and discrimination indexes for each question (the highlighted blue cells). Youâ€™ll note that they are already calculated for Question 1. You can practice with Question 1 and make sure you find the same answers as the ones provided.
Indicate your answers below.
Difficulty Index (p)
Discrimination Index (D)
Then consider what these numbers tell you about each of the items. Which items stand out to you as problematic, and why? Be sure to look at the actual test item as well as the data used to make the calculation as you formulate your explanation. In other words, your explanation should go beyond simply saying, â€œK & B said difficulty indexes should be within such and such range and this one is not in that rangeâ€. That might may be true but, so what? What does the data tell you about why that particular item scored the way it did?
For example, you might look at Question 1 and determine that the difficulty index is fairly high because out of 26 students, 20 of them got the item right. Given those numbers, one might assume the item would have a high difficulty index (i.e., itâ€™s fairly easy). But also look at the item itself. Although you may not be immediately familiar with the content of the exam, you might still note aspects of the item that could pertain or contribute to its indexes. If you do, include that in your explanation as well. Finally, consider the item analysis data including what answers the students selected. What does that information tell you about why questions might or might not be problematic?