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Discrimination Item Discrimination is the degree to which students with high overall exam scores also got a particular item correct. It is often referred to as Item Effect, since it is an index of an item’s effectiveness at discriminating those who know the content from those who do not.
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Dec 10, 2023 · Item Discrimination is a critical concept in the field of Learning and Development (L&D). It refers to the ability of an assessment item to differentiate between high and low performers. In other words, it measures how well a test question can distinguish between those who have mastered the material and those who have not.
Understand item discrimination, a significant criterion in assessing the usefulness of test items. Improve your evaluation strategies with our expert guidance. In the quest for top-quality educational assessments, item discrimination emerges as a critical statistical tool.
Item Discrimination is a measure of how well an item (i.e. a question) distinguishes between those with more skill (based on whatever is being measured by the test) from those with less skill. Discrimination Index. The principal measure of item discrimination is the discrimination index.
- 1 Discrimination Index
- Cial Interest Topic 7.2: Item Analysis For Constructed-Response Items
- 2 Item Discrimination on Mastery Tests
- Item-Total Correlation Coefficients.
- 3 Item Discrimination on Typical-Response Tests
- 4 Difficulty and Discrimination on Speed Tests
- 5 Examples of Item Difficulty and Discrimination Indices
One popular method of calculating an index of item discrimination is based on the difference in performance between two groups. While there are different ways of selecting the two groups, they are typically defined in terms of total test performance. One common approach is to select the top and bottom 27% of test takers in terms of their overall pe...
Our discussion and examples of the calculation of the item difficulty index and discrimination index used examples that were dichotomously scored (i.e., scored right or wrong, 0 or 1). While this procedure works fine with selected-response items (e.g., true–false, multiple choice), you need a slightly different approach with constructed-response it...
As we noted previously, the item difficulty indexes on mastery tests tend to be higher (indicating easier items) than on tests designed primarily to produce norm-referenced scores. This is because with mastery testing it is usually assumed that most examinees will be successful. As a result, on mastery tests it is common for items to have average p...
Another approach to examining item discrimination is to correlate performance on the items (scored as either 0 or 1) with the total test score. This is referred to as an item-total correlation. The total test score is usually the total number of items answered correctly (unadjusted) or the total number of items answered correctly omitting the item ...
Item-total correlations can also be used with typical-response tests. For example, consider a test designed to measure “sensation-seeking” tendencies using true–false items. Below is an example of an item that might be on such a test: If all “True” responses are scored “1” and indicate a tendency to engage in sensation-seeking behaviors and all “Fa...
Based on our discussion up to this point, it should be clear that there are situations where the interpretation of indices of item difficultyand discrimination are complicated. One situation where the interpretation of item analysis results is complicated is with “speed tests.” On speed tests, performance depends primarily on the speed of performan...
To illustrate the results of common item analyses, we will present a few examples based on items administered in our upper-division undergraduate Test and Measurement class. We will present three examples to illustrate some common patterns. This is an easy item that almost all students answer correctly. Since it is so easy, it does not discriminate...
- Cecil R. Reynolds, Robert A. Altmann, Daniel N. Allen
- 2021
Oct 2, 2023 · Item discrimination in testing refers to the extent to which a particular item or question differentiates between test takers who possess different levels of the construct being measured (e.g., knowledge, abilities, skills). Several factors can lead to item discrimination:
May 6, 2019 · Abstract. Factor loadings and item discrimination parameters play a key role in scale construction. A multitude of heuristics regarding their interpretation are hardwired into practice—for example, neglecting low loadings and assigning items to exactly one scale.
