**15. Item analysis application**

**Figure 1**: In this Example 1. The number of examinees was 21. The number of test items (Total possible) is 40.


#### **Figure 1.**

*Standard item analysis of mid-course examination. The total number of items is 40, and the total number of the examinee is 21. The KR20 is 0.82. Pt.Biserial: Point biserial correlation, Disc Index: discrimination index, Correct: number and percentage of the correct answer (difficulty index), Pct. Incorrect: percentage of an incorrect answer.*

The highest and lowest scores were 38 and 14 respectively.

The class average (mean) (30.3) is more than the class median (30) which represents a positively skewed distribution of examinee scores. Despite this, examinee scores may show normal ball-shape distribution. If the median is larger than the average (mean), the examinee scores will be negatively skewed distribution. Average equals median, the examinees' scores are symmetrically (zero skewed) and normally distributed with ball-shaped.

The KR20 (Cronbach's alpha) is 0.82 which is an acceptable value for most of the authors. Such value of internal consistency of exam allows deciding pass/fail. Lower values put the exam in questionable status.

• Item 1: the difficulty index is 85.7% (easy). Although it has high discrimination power (DE = 0.6, Pbiserial = 0.58), two distractors are non-functional (B, C).

Comment: the item needs reediting. Distractors B and C need to be revised or changed by more plausible ones before being re-used.

• Item 2: the difficulty index is 100% (easy). It has low discrimination power (DE = 00, Pbiserial = 00), all distractors are non-functional.

Comment: the item needs major revision or rewriting. This item is absolutely easy with no difficulty or discrimination index. Such items should be removed from the question bank and removal from the exam is considered valid.

• Item 6: the difficulty index is 66.7% (moderate). It has high discrimination power (DE = 0.6, Pbiserial = 0.43) and all the distractors are functional.

Comment: The item has acceptable indices. Such items can be saved in the question bank for further use. The distractors need to be updated to have more efficiency.

• Item 7: the difficulty index is 28.6% (difficult). Although it has high discrimination power (DE = 0.67, Pbiserial = 0.39), all the distractors are functional.

Comment: The item has acceptable indices. Such items can be saved in the question bank for further use. The distractors need to be updated to have more efficiency.

• Item 8: the difficulty index is 76.2% (moderate). This item has a negative discrimination index (−0.33) and poor Pbiserial (0.04). Only one distractor is functional (C). The negative discrimination index is caused by the increased number of students in the lower account (27%) than those in the upper account (27%).

Comment: although the item has a moderate difficulty index, but is poorly discriminating. Such an item needs major revision.


#### **Figure 2.**

*Standard item analysis of Mid-course examination. The total number of items is 40, and the total number of examinee is 25. The KR20 is 0.74. Pt.Biserial: Point biserial correlation, Disc Index: discrimination index, Correct: number and percentage of the correct answer (difficulty index), Pct. Incorrect: percentage of an incorrect answer.*
