A statewide random sampling of seven groups of professional educators (N=90) and 30 parents of learning disabled (LD) students were compared for their degree of agreement on the Modified Component Disability Instrument. Professionals included teachers of LD adolescents, remedial reading teachers, school psychologists, speech clinicians, school principals, and school counselors. The Bartlett Test of homogeneity of variance was applied to each of the 20 components of disabilities measured by the instrument for the professional and parent populations. Results suggested that no one group of professionals or parents would be considered to be an "expert" by their restricted variance when making decisions of the prevalence of a majority of component disabilities as they are associated with either the LD or nonLD populations. Tables with statistical data are included as is a copy of the Modified Component Disability Measure. (Author/SB)