This report presents the results of the third administration of the Delaware Student Testing Program (DSTP). These results are part of a long-term effort to gather data on the educational progress of Delaware students and to use the data to inform decisions about instruction. Reading, writing, and mathematics results are summarized in this report; social studies and science data for grades 8 and 11 are to be reported in fall 2000. The reading and mathematics data are reported as National Percentile Rankings (NPRs), Standards-Based Scores (SBSs), and Performance Levels (PLs). The NPRs (not available for writing) come from a subset of items embedded in the test that were also given to a representative sample of students across the country. The SBSs measure students' progress toward Delaware standards in each content area, and PLs tell how students are performing relative to the state's content standards. DSTP data will enable educators and the public to determine how well Delaware's students are performing over time. To determine how well educators are meeting the needs of all learners, DSTP data are disaggregated by gender, race/ethnicity, free/reduced price mean eligibility, Title I status, disability, English proficiency, and migrant status. Appendix A contains 1999 state and district data, and Appendix B contains school results. Appendix C contains data disaggregated by group, grade, and subject, and Appendix D contains school level scores by free and reduced price meal eligibility. (Contains 40 charts and 39 tables.) (SLD)