STATE DISPARITIES IN THE DIAGNOSIS AND PLACEMENT OF PUPILS WITH LEARNING-DISABILITIES

We investigated the hypothesis that interstate disparities in the diag nosis of pupils with learning disabilities (LD) are more strongly corr elated with demographic and sociopolitical factors than with the biolo gical prevalence of the disability. We also investigated the relations hip of these factors to placement practices. Thirteen independent vari ables representing state characteristics were simultaneously regressed against each of seven static dependent variables, measuring diagnosti c and placement practices in 1989, and two dynamic dependent variables , measuring changes in practices between 1976 and 1989. Results of the regression indicated that although demographic and sociopolitical fac tors explained none of the total prevalence of the four most common ph ysical disabilities (adjusted R-2[(R) over bar(2)] = 9), they did expl ain to a moderate degree the state prevalence of LD ((R) over bar(2) r anged from .15 to .28), and were more predictive still depending on me asure of LD prevalence. Moreover, these same factors strongly predicte d the extent to which states mainstreamed their pupils (R) over bar(2) =.59) and the size of the nonmainstreamed cognitively disabled (LD an d educable mentally retarded)population ((R) over bar(2) =.56).