Factors influencing the selection of standardized tests for the diagnosis of specific language impairment

Standardized tests are one of the primary assessment tools used by speech-language pathologists (SLPs) to diagnose child language impairment. Numerous child language tests are commercially available; however, it is unknown what factors lead clinicians to select particular tests to use in clinical practice. This study investigated whether the quality of standardized tests, as measured by the test's psychometric properties, is related to how frequently the tests are used in clinical practice.

A total of 364 SLPs completed a survey regarding how frequently they used specific standardized tests when diagnosing suspected specific language impairment (SLI). The test manuals for 55 tests were reviewed to determine whether test characteristics, such as test reliability, validity, and accuracy, correlated with the frequency of test use.

The most frequently used standardized tests were omnibus measures (e.g., Clinical Evaluation of Language Fundamentals-Fourth Edition [Semel, Wiig, & Secord, 2003], Preschool Language Scale, Fourth Edition [Zimmerman, Steiner, & Pond, 2002]) and single-word vocabulary measures (e.g., Peabody Picture Vocabulary Test, Fourth Edition [Dunn & Dunn, 2007]). Publication year was the only test characteristic that correlated significantly with the frequency of test use.

The quality of a standardized test, as measured by the test's psychometric properties, does not appear to influence how frequently a test is used. These results highlight the need for increased evidence-based practice when diagnosing children with language impairment.