This guide explains results and other information contained in the "Test Item Analysis Report," the "School Report," and the "District Report" for the Massachusetts Comprehensive Assessment System (MCAS) tests for spring 1999. It is designed to help teachers, administrators, and parents understand the MCAS testing program. The guide contains this section: (1) "Document Purpose"; (2) "General Guidelines for the Interpretation and Use of MCAS Reports"; (3) "Understanding the 'Test Item Analysis Report'"; and (4) "Understanding the 'School' and 'District Reports.'" Appendixes contain information on converting raw scores to scale scores, the MCAS reporting categories, content-specific performance level definitions, a list of the MCAS assessment development committee members, and MCAS-related references. (Contains 3 tables and 11 references.) (SLD)