Abstract
Group-matching designs are commonly used to identify the diagnosis-specific characteristics of children with developmental disabilities. In this paper, we address three issues central to the use of this design. The first concerns the α level to be used for considering groups to be matched on the control variable(s). The second involves the measurement characteristics of the control and target variables. We discuss the properties of standard scores, raw scores, and age equivalents and argue against the use of age equivalents. In addition, we consider the appropriateness of the commonly made prediction that groups that are matched for a control variable such as language ability or nonverbal reasoning ability but are not matched for chronological age should perform at equivalent levels on the target variable. Finally, we discuss issues related to the interpretation of significant between-group differences on the target variable, assuming groups are well-matched on the control variables, and describe the benefits of a method that focuses on characterizing a disorder on a case-by-case basis and then aggregating the cases, using the measures of sensitivity and specificity from signal detection theory.
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Carpentieri, S., & Morgan, S. B. (1996). Adaptive and intellectual functioning in autistic and nonautistic retarded children. Journal of Autism and Developmental Disorders, 26, 611-620.
Carter, A. S., Volkmar, F. R., Sparrow, S. S., Wang, J-J., Lord, C., Dawson, G., Fombonne, E., Loveland, K., Mesibov, G., & Schopler, E. (1998). The Vineland Adaptive Behavior Scales: Supplementary norms for individuals with autism. Journal of Autism and Developmental Disorders, 28, 287-302.
Cohen, J. (1990). Things I have learned (so far). American Psychologist, 45, 1304-1312.
Cook, E. H. (1998). Genetics of autism. Mental Retardation and Developmental Disabilities, Research Reviews, 4, 113-120.
Dunn, L. E., & Dunn, L. E. (1981). Peabody Picture Vocabulary Test-Revised. Circle Pines, MN: American Guidance Service.
Dunn, L. E., & Dunn, L. E. (1997). Peabody Picture Vocabulary Test, 3rd ed. Circle Pines, MN: American Guidance Service.
Elliott, C. D. (1990). Differential Ability Scales. San Diego: Harcourt Brace Jovanovich.
Frangiskakis, J. M., Ewart, A. K., Morris, C. A., Mervis, C. B., Bertrand, J., Robinson, B. F., Klein, B. P., Ensing, G. J., Everett, L. A., Green, E. D., Pröschel, C., Gutowski, N., Noble, M., Atkinson, D. L., Odelberg, S., & Keating, M. T. (1996). LIM-kinase 1 hemizygosity implicated in impaired visuospatial constructive cognition. Cell, 86, 59-69.
Fenson, L., Dale, P. S., Reznick, J. S., Thal, D., Bates, E., Hartung, J. P., Pethick, S., & Reilly, J. S. (1993). MacArthur Communicative Development Inventories: User's guide and technical manual. San Diego, CA: Singular.
Frick, R. W. (1995). Accepting the null hypothesis. Memory & Cognition, 23, 132-138.
Harcum, E. R. (1990). Methodological vs. empirical literature: Two views on the acceptance of the null hypothesis. American Psychologist, 45, 404-405.
Jarrold, C., Baddeley, A. D., & Phillips, C. E. (2002). Verbal short-term memory in Down syndrome: a problem of memory, audition, or speech? Journal of Speech, Language, & Hearing Research, 45, 531-544.
Klein, B. P., & Mervis, C. B. (1999). Cognitive strengths and weaknesses of 9-and 10-year-olds with Williams syndrome or Down syndrome. Developmental Neuropsychology, 16, 177-196.
Klein-Tasman, B. P., & Mervis, C. B. (2003). Distinctive personality characteristics of children with Williams syndrome. Developmental Neuropsychology, 23, 271-292.
Kraemer, H. C. (1988). Assessment of 2 × 2 associations: Generalization of signal-detection methodology. The American Statistician, 42, 37-49.
McCarthy, D. (1972). McCarthy Scales of Children's Abilities. New York: The Psychological Corporation.
Mervis, C. B. (2004). Cross-etiology comparisons of cognitive and language development. In M. L. Rice & S. Warren (Eds.), Developmental language disorders: From phenotypes to etiologies (pp. 153-185). Mahwah, NJ: Lawrence Erlbaum.
Mervis, C. B., & Robinson, B. F. (1999). Methodological issues in cross-syndrome comparisons: Matching procedures, sensitivity (Se), and specificity (Sp). Commentary on M. Sigman & E. Ruskin, Continuity and change in the social competence of children with autism, Down syndrome, and developmental delays. Monographs of the Society for Research in Child Development, 64(256), 115-130.
Mervis, C. B., & Robinson, B. F. (2003). Methodological issues in cross-group comparisons of language and/or cognitive development. In Y. Levy & J. Schaeffer (Eds.), Language competence across populations: Toward a definition of specific language impairment (pp. 233-258). Mahwah, NJ: Lawrence Erlbaum.
Mervis, C. B., Robinson, B. F., Bertrand, J., Morris, C. A., Klein-Tasman, B. P., & Armstrong, S. C. (2000). The Williams Syndrome Cognitive Profile. Brain and Cognition, 44, 604-628.
Morris, C. A., Mervis, C. B., Hobart, H. H., Gregg, R. G., Bertrand, J., Ensing, G. J., Sommer, A., Moore, C. A., Hopkin, R. J., Spallone, P., Keating, M. T., Osborne, L., Kimberley, K. W., & Stock, A. D. (2003). GTF2I hemizygosity implicated in mental retardation in Williams syndrome: Genotype/phenotype analysis of 5 families with deletions in the Williams syndrome region. American Journal of Medical Genetics, 123A, 45-59.
Paterson, S. (2001). Language and number in Down syndrome: The complex developmental trajectory from infancy to adulthood. Down Syndrome Research and Practice, 7, 79-86.
Robinson, B. F., & Mervis, C. B. (1998). Disentangling early language development: Modeling lexical and grammatical development using an extension of case-study methodology. Developmental Psychology, 34, 363-375.
Rothbart, M. K., & Ahadi, S. A. (1994). Temperament and the development of personality. Journal of Abnormal Psychology, 103, 55-66.
Rothbart, M. K., Ahadi, S. A., & Hershey, K. L. (1994). Temperament and social behavior in childhood. Merrill-Palmer Quarterly, 40, 21-39.
Semel, E., Wiig, E. H., & Secord, W. A. (2003). Clinical Evaluation of Language Fundamentals, 4th ed. San Antonio, TX: Psychological Corporation.
Siegel, B., Vukicevic, J., Elliott, G. R., & Kraemer, H. C. (1989). The use of signal detection theory to assess DSM-IIIR criteria for autistic disorder. Journal of the American Academy of Child & Adolescent Psychiatry, 28, 542-548.
Sigman, M., & Ruskin, E. (1999). Continuity and change in the social competence of children with autism, Down syndrome, and developmental delays. Monographs of the Society for Research in Child Development, 64(256), 1-114.
Sparrow, S. S., Balla, D. A., & Cicchetti, D. V. (1984). Vineland Adaptive Behavior Scales—Interview Edition. Circle Pines, MN: American Guidance Service.
Tellegen, A. (1985). Structures of mood and personality and their relevance to assessing anxiety, with an emphasis on self-report. In A. H. Tuma & J. D. Maser (Eds.), Anxiety and the anxiety disorders (pp. 681-716). Hillsdale, NJ: Lawrence Erlbaum.
Williams, K. T. (1997). Expressive Vocabulary Test. Circle Pines, MN: American Guidance Service.
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Mervis, C.B., Klein-Tasman, B.P. Methodological Issues in Group-Matching Designs: α Levels for Control Variable Comparisons and Measurement Characteristics of Control and Target Variables. J Autism Dev Disord 34, 7–17 (2004). https://doi.org/10.1023/B:JADD.0000018069.69562.b8
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DOI: https://doi.org/10.1023/B:JADD.0000018069.69562.b8