A valid test :
Measurement exactly what it proposes to measure (content-related validity )
Does not measure unrelated or interfering variables
Measures whether the criterion of the test has been achieved (criterion-related validity)
Relies on empirical evidence
Is supported by research-based argument (construct-related validity)
Offers useful, meaningful information about the test-taker’s ability
The impact of assessment before and after (washback) (consequential validity)
The students who receive the test their relevant and useful(face-validity)