Question
We administer the Peabody to kindergarten students at the beginning of school and again at the end of school. Do you recommend using the same Form each time or would you, for example, use Form A in the fall and Form B in the spring? Could you please expla
Answer
An alternate or equivalent form usually is used with a second administration of a test in order to protect against threats to test validity, such as practice effect due to familiarity with test items, cheating, teaching to the test, etc. If you know of or suspect the possibility of such threats, use the alternate form for the second administration. If, however, you are sure that the test and test items are secure from any attempts at cheating or teaching to the test, and the two administrations are separated as you indicate by 8 or 9 months, you probably could safely use the same form both times. When in doubt, use the alternate form.
I assume you are using the Peabody Picture Vocabulary Test (PPVT), not the Peabody Individual Achievement Test (PIAT). The current edition (PPVT-4) includes a "growth scale value (GSV) score designed for measuring change over time." The test manual describes how to interpret the GSV score and how it differs from a standard score.
Finally, I hope that the PPVT is not the only measure of growth that you are using with your Kindergarten students. The PPVT-4 manual cautions examiners that "the PPVT-4 instrument measures only hearing vocabulary, which is just one aspect of the complex domain of language development."
Please visit SpeechPathology.com and browse our courses to learn more about this topic and to view a variety of live, recorded and text-based courses in the field.
Les Aungst holds B.A., M.S. and Ph.D degrees in speech-language pathology. He has more than 10 years' clinical experience as a speech-language pathologist with preschool and school-age children, and more than 30 years in higher education as a researcher, instructor, supervisor and administrator. Courses taught have included diagnostic procedures in speech-language pathology and the evaluation of appraisal techniques.