Factors Affecting Validity

1. Inappropriateness of the test item.

Measuring the understandings, thinking skills, and other complex types of achievement with test forms that are appropriate only for measuring factual knowledge will invalidate the results (Asaad, 2004).

2. Directions of the test items.

Directions that are not clearly stated as to how the students respond to the items and record their answers will tend to lessen the validity of the test items (Asaad, 2004).

3. Reading vocabulary and sentence structure.

Vocabulary and sentence structures that do not match the level of the students will result in the test of measuring reading comprehension or intelligence rather than what it intends to measure (Asaad, 2004).

4. Level of difficulty of the test item.

When the test items are too easy and too difficult they cannot discriminate between the bright and the poor students. Thus, it will lower the validity of the test (Asaad, 2004).

5. Poorly constructed test items.

Test items that unintentionally provide clues to the answer will tend to measure the students’ alertness in detecting clues and the important aspects of students’ performance that the test is intended to measure will be affected (Asaad, 2004).

6. Length of the test items.

A test should have a sufficient number of items to measure what it is supposed to measure. If a test is too short to provide a representative sample of the performance that is to be measured, validity will suffer accordingly Asaad, 2004).

7. Arrangement of the test items.

Test items should be arranged in increasing difficulty. Placing difficult items early in the test may cause mental blocks and it may take up too much time for the students; hence, students are prevented from reaching items they could easily answer. Therefore, the improper arrangement may also affect validity by having a detrimental effect on students’ motivation (Asaad, 2004).

8. Pattern of the answers.

A systematic pattern of correct answers and this will lower again the validity of the test (Asaad, 2004).

9. Ambiguity.

Ambiguous statements in test items contribute to misinterpretations and confusion. Ambiguity sometimes confuses the bright students more than the poor students, causing the items to discriminate in a negative direction (Asaad, 2004).


Asaad, Abubakar S. (2004). Measurement and Evaluation Concepts and Application (Third Edition).Manila: Rex Bookstore Inc.