Due to the recent and unprecedented emphasis on educational accountability, assessment selection has become an important consideration. There are various types of assessments that can be used to measure student performance. Criterion- Referenced Tests (CRT) and Norm-Referenced Tests (NRT) are two types of assessments that measure performance, but relative to different criteria. Additionally, scores are reported in different formats, interpreted differently and target different content.
Difference Between NRT and CRT
Tests based on norms measure the performance of a group of test takers against the performance of another group of test takers. This type of assessment result can used to compare the performance of seventh graders in a particular school system to the performance of a broader, and perhaps more diverse (nationally or state-wide), group of seventh graders. Criterion based tests measure the performance of test takers relative to particular criteria covered in the curriculum. In other words, CRT test scores can be used to determine if the test taker has met program objectives.
Pros and Cons
The advantages and disadvantages of norm referenced tests vs criterion referenced tests depends on the purpose and objective of testing. Norm referenced tests may measure the acquisition of skills and knowledge from multiple sources such as notes, texts and syllabi. Criterion referenced tests measure performance on specific concepts and are often used in a pre-test / post-test format. These tests can also be used to determine if curriculum goals have been met. The content of NRT is much broader and superficial than the content measured by CRT.
Differing Methods of Test Administration
Norm referenced tests must be administrated in a standardized format, while criterion referenced tests do not necessitate a standard administration. Since norm referenced tests measure the performance of test takers to other test takers, it is essential that testing conditions closely match those of the norm setting test takers. Therefore, the test administration is scripted. This is in sharp contrast to criterion referenced testing administration.
Score Reporting and Interpretation
Scores are reported differently for criterion referenced and norm referenced tests. Criterion referenced test results are reported in categories or range. For instance, performance may be reported as not proficient, proficient or very proficient. The interpretation of this performance is obvious and directly related to the acquisition of stated curriculum objectives. The reporting of results for a norm referenced test is accomplished by a percentile rank. A test taker who scores in the 95th percentile has performed better than 95% of the individuals taking the test. In general, scoring at the 50th percentile is average and indicates that the test taker has scored better than 50% of the individuals testing.