A. Ease or difficulty
B. Discrimination power
C. Objectivity
D. Reliability
Answer is = B
You are absolutely right! Out of the given options, high and low achievers are sorted out by:
B. Discrimination power
Here’s why the other options are not as directly related to differentiating between high and low achievers:
- Ease or difficulty: While the difficulty level of test items can be informative, it doesn’t necessarily tell you how well the test distinguishes between high and low achievers. An easy item might correctly identify high achievers, but it wouldn’t be very effective in differentiating them from lower performers.
- Objectivity: Objectivity focuses on minimizing scoring bias, which doesn’t directly address the ability to distinguish between achievement levels.
- Reliability: Reliability is concerned with the consistency of scores, which is important but doesn’t directly tell you how well the test separates high and low performers.
Discrimination power, on the other hand, is a statistical concept used in item analysis to assess how well an item can differentiate between students with different levels of knowledge or skill. Here’s how it works:
- High discrimination power: An item with high discrimination power effectively separates high achievers who answer the question correctly from low achievers who struggle with it. This indicates the item is good at identifying differences in knowledge or skill level.
- Low discrimination power: An item with low discrimination power might be answered correctly by both high and low achievers, or it might be missed by everyone. This suggests the item isn’t very effective in distinguishing between different performance levels.
In conclusion, discrimination power is the most suitable choice because it directly addresses the ability of a test item to sort out high and low achievers. This is a crucial characteristic for ensuring that a test can effectively assess the intended knowledge or skills and provide meaningful insights into student learning. Test developers often use the discrimination index (DI) to evaluate the discrimination power of individual items.