This paper provides a list of variables identified as important to learning that emerged from a "meta-review" of the professional literature, as well as a summary of consensus ratings of these variables by professionals in the field. The variables are organized into six major categories: (1) state and district variables; (2) out of school contextual variables; (3) school-level variables; (4) student variables; (5) program design variables; and (6) implementation, classroom, instruction, and climate variables. A questionnaire with the list of variables was sent to six professional groups (researchers, policy makers, special and regular education teachers, school psychologists, and principals). A total of 1,123 persons, who were asked to rate each of the 228 variables according to a 3-point scale, responded to the questionnaire. Variables rated by the entire group as being of high importance and moderate importance in arranging learning environments were identified as "effective practices." (Author/DB)