The challenge of interpreting test scores.

In summary, it is clear that the practicing speech-language pathologist needs to demonstrate a working knowledge of some of the basic principles of psychometric measurement in order to effectively interpret the results of commonly employed speech and language tests. It is important that the SLP is familiar with the process used for standardization of tests, as well as the difference between norm-referenced and criterion-referenced tests. It is also critical that the SLP be aware of issues related to validity and reliability, as well as various types of scores associated with tests. While a background in statistics is helpful, it should be noted that the manual that accompanies each standardized test generally includes definitions, explanations, and conversion tables designed to assist the SLP in administering and interpreting the results. Careful study of the manual and a review of any questionable items via an appropriate textbook should assist the SLP in the literal interpretation of test results. In addition to the information obtained from standardized testing, it is also important to consider results of observation of the client and informal testing in order to accurately characterize speech and language behavior.