
Clinical Café by Debby Hutchins, MS, CCC-SLP
Previously we talked about scoring tests and writing diagnostic reports that give a vivid picture of a client. We were, in essence, talking about levels of interpretation. The topic for this month’s Clinical Café covers in-depth analysis and interpretation. You definitely have some options with psychometrically sound tests to make them clinically useful and sophisticated. Are you getting the most from your test and manual? Read on!
Interpreting Performance in Layers
In the Goldman-Fristoe Test of Articulation, Second Edition manual (page 5), also known as the GFTA-2, the authors discuss levels of analysis that lead to different layers of interpretation. If you use the Level 1 or Level 2 scoring procedures, you have different amounts of information for interpreting the normative scores and the examinee’s overall performance. As you read in the manual, Level 1 scoring allows a global interpretation of the examinee’s normative scores with respect to his or her same-aged peers. Level 2 scoring gives the additional categorization of errors—how is the sound incorrect—that deepens to another layer of interpretability.
If there are numerous errors and/or the speech sample is highly unintelligible, then you may need a still deeper layer of interpretation. The psychometrically linked partner test to the GFTA-2 is the Khan-Lewis Phonological Analysis, Second Edition (KLPA-2), which organizes sound errors into 10 phonological processes divided into three process areas (manual, pages 10-14). Keep in mind that you can start right in with this layer, if your clinical judgment tells you that enough sound errors exist to warrant a process-based approach that addresses the examinee’s sound system as a rule-governed system. What’s more, you can analyze 34 additional phonological processes descriptively for even more in-depth interpretation.
One important point to remember: When you do articulation testing only, as with the GFTA-2, you should not refer to errors as phonological process errors. This terminology is available only with a phonological process-based test instrument such as the KLPA-2.
Interpreting Performance in Scores
Each normative score has opportunities and limitations in its interpretability. That is the reason for so many types of normative scores—each one has a specific use and value. You may want to put a bookmark in each of your test manuals at the following pages for easy reference:
- GFTA-2 pages 31-33
- KLPA-2 pages 42-48
- EVT pages 35-40
- CASL pages 89-98
- OWLS LC/OE pages 98-102
- OWLS WE pages 120-125
On these pages, you will find information on interpreting each of the normative scores appropriately. This is important because all too often these scores can be misunderstood and then inadvertently misused.
Interpreting Performance for Intervention and Collaboration
After completing professional analysis and interpretation of test results, you then explain these results to parents and teachers and plan intervention. The descriptive analysis worksheets for the Oral Written and Language Scales (OWLS LC/OE and WE) and Comprehensive Assessment of Spoken Language (CASL) can assist you in that process (These worksheets are available to you through our Web site www.speechandlanguage.com and are located on the right-hand side of each product page.) Likewise, the KLPA-2 provides a vehicle for describing interpretive results in the Phonological Summary and Progress Report. This handy form can be used to explain sound errors in detail, assist in developing goals and benchmarks (objectives), and provide a method of reporting progress over time.
2005—A Resolution
New Year is the time for resolutions. Consider making this resolution your own: Start utilizing all the levels of analysis and interpretation that your tests and manuals provide. Personally, I prefer this resolution to exercise regimens or diets. Bring on the chocolate!











Overall, test-retest reliability is an index of temporal stability. It tells how much the individual’s normative score might possibly change on retesting if a period of time has elapsed between test administrations. Change could reflect the person’s growth or fluctuation in the ability being measured, random differences in performance, or the individual’s recollection of the earlier administration. A test-retest coefficient is a statistical measure that is obtained by administering the same test twice, with a certain amount of time between administrations, and then correlating the two score sets. Reliability between two parallel forms with different content is known as an alternate-form coefficient (as in the
Determine why you are conducting a retest: Did the examinee’s performance fall below your expectations due to illness, bad day, test anxiety, student behavior, etc? If this is the case, as soon as the examinee is up to it, you should be able to retest, especially if you use a parallel form. Are you involved in a pre/post test situation where you are attempting to ascertain gain? If so, you’d want to schedule the second administration after the completion of instruction or therapy to determine the effectiveness of the treatment.Has the student recently transferred from a different school? If the original test administration was done in another school or setting by a clinician that you do not know, and you question the reported results, you may choose to re-test.
**The PPVT-III is unique among Pearson speech-language tests in that it has parallel forms (Forms A & B). As written in the Alternate-Forms Reliability Coefficients section on page 48 of the PPVT-III manual, most test subjects were given both forms of the test in the same day.
Test Content and Test-Retest Reliability: A Related Consideration
Yes, it is difficult to know sometimes what you can and can’t make decisions on. Test standardization is a rigorous process and we appreciate professionals being concerned about “following the rules.” At the same time, no test can anticipate all the situations and nuances of the clinical arena, so there is a point at which the rules end and your clinical judgment begins. We’re happy to continue to help you clarify the line on which to “dance.”If you want more information on standardized test development, the Development Team at Pearson’s Assessment group is in the process of creating an ASHA-approved CE presentation (available end of summer) on the basics of assessment. If you are interested in scheduling a continuing education activity for your school, district, or your state speech-language-hearing association, please contact: