Interpretability
Linn & Gronlund (2000) defines interpretability as the degree to which the scores of a test are assigned a meaning based on a criterion or norm for a particular purpose is known as interpretability.  The raw score is simply the number of points perceived on a test when the test has been scored according to the directions. For example, a student X answered 25 items correctly on an arithmetic test, therefore student X has a raw score of 25. To make a raw score means it is converted into a description of the specific task that the student can perform is the process of interpretability.

Criterion-referenced and standard-based interpretation

A test about the specific kind of domain is directed at a desire for criterion-referenced and standards-based interpretations. Criterion-referenced and standard-based interpretation of test results is most meaningful when the test has been designed for this purpose. This involves designing a test that measures achievement domain, which is homogeneous, delimited, and clearly specified, enough items for each interpretation, Items neither easy nor difficult, Items not only selection type but all other types and Items directly provide relevance to objectives (Linn & Gronlund, 2000).

Norm-referenced interpretation

Swian et al (2000) assert that norm-referenced interpretation tells us how an individual compares with other persons who have taken the same test. The simplest way of comparison in the classroom is ranking from highest to lowest where an individual score falls. For more meaningful and well-defined characteristics of interpretation, raw scores are converted into derived scores which are numerical reports of test performance on a score scale.

Uses of interpretability

Teachers keep records of the students, overtime and improve their instruction by interpreting the scores of a test. The students can see their level of performance related to other colleagues in their class by looking at the interpretation of their test scores. Parents easily understand the actual performance of their children and decide what to do and what not to do. The administration uses the interpretation of test scores to present the position of the school in terms of students learning. The Researchers make inferences by interpreting the scores of tests as their data collection tool (Linn & Gronlund, 2000).

Strengths

Swain et al (2000) share the following strengths and weaknesses of interpretability of test scores.
•      More information can be presented to the audience using a small number of illustrations.
• Students' achievements are qualitatively expressed other than numerical values.
•       Students are measured relative to the average group.
•      Tables for norms are already given, so looking at the tables, interpretation becomes easy.

Weaknesses

•      If the task is not selected appropriate to the domain being measured the scores will be misinterpreted.
•       A large number of items are needed to ensure correct interpretation, which takes time to carry out calculations.
•       If item analysis is not done properly which means easy items are included, then the low achievers will not know about what they can do or cannot do.
•      Norms are generalized for all students by a pilot test but not taken care of individual differences in overall educational settings.

    References

Linn, R. L., & Gronlund, N.E. (2000). Measurement and assessment in teaching (8thed.). Delhi: Pearson Education.

Swain, S. K., Pradhan, C., & Khotoi, S. P. K. (2000). Educational measurement: Statistics and 
            guidance. Ludhiana: Kalyani.