Methods of Assessment
- 17. What are the main requirements of an efficient test? - - 18. The problem of test rubric: How far do format and instructions affect assessment?
- - 19. What is test discrimination? When is it not needed?
- 17. What are the main requirements of an efficient test?
- Reliability, Validity (see questions 17-20)
- Comparison & Discrimination (see question 24)
- Practicality.
Practicality - How long will the test take? Rest of the class? Equipment? How long will it take to mark? How many people are involved? [Expense]. Reproduction of test materials in quantity? [Storage]? Efficient filing?
- 18. The problem of test rubric: How far do format and instructions affect assessment?
Instructions given to students on how to do test are an important aspect of validity. The wording should be chosen very carefully, especially at lower levels. Familiarity with the form of the test. You should use L1 if this is the same for all students, for clarity.
Wider sense of "rubric": all arrangements made by the setter to enable the student to give attention to content: layout, length of pauses in LC etc.
If the rubric is poor, you will not be able to tell from the test whether students have learnt the required skill or not. Note: use of L1 in placement test rubrics.
- 19. What is test discrimination? When is it not needed?
Discrimination is the capacity of a test to discriminate among different candidates and to reflect the differences in the performances of the individuals in the group. E.g. 70% means nothing at all unless all other scores obtained in the test are known. Tests on which almost all candidates score 70% clearly fail to discriminate between various students.
Tests which are to be standardised (intended for a large test population and first tried out on a representative sample of testees) - SAMPLING: the small sample mirrors the much larger group for whom the test is intended.
The results of this test are then examined to determine the extent to which it discriminated between individuals who are different. Discriminatory powers must be established.
Discriminatory powers may be needed with PLACEMENT TESTS, but may not be needed with DIAGNOSTIC TESTS or tests concerned with how much of a syllabus students have mastered (i.e. administered internally).
Also with Criterion-Referenced Tests / Performance tests, all you may be interested in is whether or not the testees can perform the criterion, though note the existence of the third group: learning to perform - some right; some wrong.