1. Teacher referred for reason other than academic problems, psychologist found child eligible as MMR, child placed (1 child).

  2. Teacher referred for reason other than academic problems, psychologist found child eligible as MMR, child not placed (3 children).

Of 269 children referred by teachers, only 87 (32 percent) were actually placed. In 116 cases (43 percent), the IQ score secured by the psychologist actually prevented certification, being above the cutoff score for MR. Finally, in 63 cases (23 percent) of all referred children, the child was not placed despite having an IQ score permitting eligibility. Of the 153 referred children with IQ scores permitting placement in programs for MMR, less than three-fifths were actually placed (57 percent). Clearly, IQ alone did not preordain placement as MR. These data were collected in the early 1960s, when the more inclusive Heber definition was in effect in the California education code. To quote Mercer (1973b): “Clinicians are apparently assessing more than IQ test scores in making diagnoses” (p. 15). Something akin to adaptive behavior enters into the placement formula as well as numerous contextual factors including, but not limited to, parental opposition, perceived competence of the special education teacher, issues of second language acquisition, and the like.

The inclusion of adaptive behavior as a dimension defining MR has been controversial since introduced by Heber (see Clausen, 1967, 1968, 1972; Zigler et al., 1984; Zigler and Hodapp, 1986) due to the subjectivity (i.e., unreliability) it introduces into the diagnostic process. These concerns are particularly salient to the segment of children considered MMR, the category in which overrepresentation is most prominent, because the domains measured by extant scales do not tap the behaviors that prompt referral of cases of MMR. Instead, a ceiling effect is noted. Paradoxically, the segment of children for whom diagnosis is most difficult is the same segment for which the existing scales are least appropriate.

State definitions of MR continue to use the Grossman (1983) definition as a model, opting not to adopt the more current AAMR version (Luckasson, 1992). Denning et al. (2000) summarized existing state definitions and classification practices, reporting that 44 states use the Grossman definition while three used the Luckasson definition. Only one state (Massachusetts) reported that consideration of adaptive behavior was not required in diagnosing MR. However, only 14 states actually listed specific practices that needed to be considered for eligibility. This is consistent with an earlier survey by Frankenberger and Fronzaglio (1991:318), who reported:

Even though states appear to be moving toward agreement on IQ cutoffs, there is little agreement in the states’ methods of identifying deficits in adaptive behavior and academic achievement. In the current study, only 7 states delineated cutoff scores indicative of deficits in adaptive behavior.

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