A taxonomy of problems in the environment or evident in student behaviors which impede providing the necessary conditions for pupils to learn was developed by teachers of the educable mentally retarded (EMR) in Wisconsin. Of the teachers, 67% or 487 responded to a request to specify five problems along with their causes and successful and unsuccessful strategies evolved to cope with them. Problem definitions obtained numbered 1,172; a 10% random sample of 117 problems was sorted and categorized by 85 special education teachers and graduate students. First order categorized revealed 30 latent categories, and second order clustering reduced the number to 16: aggressive disrupting behavior (18%), deficits in instructional programing (17%), motivation of pupils (14%), inappropriate affective reactions (7%), hyperactivity and nervousness (7%), reactions to failure (6%), negative home environment (6%), poor personal hygiene (4%), pupil dissatisfaction with being in special classes (4%), perceptual inadequacies (2.5%), truancy (2.5%), emerging sex interests (2.5%), lack of teacher-pupil communication (2.5%), asocial behavior in multiply handicapped (2.5%), overdependency (2.5%), and overimaginative and distorted accounts (2%). Experienced sorters generated significantly more categories and made greater differentiation of the first order categories on the second order grouping. (SN)