This is an abridged, summary report of selected findings from "Pieces of the Puzzle: Factors in the Improvement of Urban School Districts on the National Assessment of Educational Progress"--a comprehensive study prepared by the Council of the Great City Schools in collaboration with the American Institutes for Research (AIR) and with funding from The Bill & Melinda Gates Foundation. The purpose of this report--exploratory as it is--is to present new data on urban school districts that have made significant and consistent gains, have demonstrated high overall performance, or have not produced consistent improvements on NAEP reading and mathematics assessments at grades 4 and 8. This report examines factors that might be driving those patterns, how alignment between state or district standards and NAEP, as well as the instructional programs and other features of the districts, might be affecting results, and what may be needed to further improve urban public schooling nationwide. The study also provides a preliminary framework for how future analyses might be conducted as more city school systems participate in TUDA. The results of this exploratory study are encouraging because they indicate that urban schools are making significant academic progress in reading and mathematics and may be catching up with national averages. The findings have special import because they suggest some reasons for this progress and the steps that might be required to accelerate this headway, particularly as the new common core standards are being implemented. Research Advisory Panel and Research Panel are appended. A bibliography is included. (Contains 16 tables, 4 figures and 24 footnotes.) [For related reports, see "Addendum to Pieces of the Puzzle: Recent Performance Trends of Urban Districts--A Closer Look at 2009 NAEP Results" (ED528219) and "Pieces of the Puzzle: Factors in the Improvement of Urban School Districts on the National Assessment of Educational Progress" (ED528220).]