Gaps in school achievement among racial/ethnic groups and between students from different socioeconomic circumstances are well documented. They are wide and persistent, well known and widely acknowledged. This report focuses on the conditions and experiences that create and perpetuate achievement gaps. It is the second edition of the report "Parsing the Achievement Gap: Baselines for Tracking Progress," published in 2003. The report focuses on the many antecedents of differences in school achievement. The review begins by identifying school and home conditions that the research community largely agrees are associated with school achievement, although there are points of disagreement. Research is a continuing process of thesis and antithesis, and what seems to be established may be challenged. This new report adds another dimension to the original report by assessing whether there have been changes in these critical factors since then, and judges whether any progress has been made in closing the gaps in these correlates of achievement. The report concludes that minority students and poor students continue to face conditions that undermine school achievement. The authors advocate that policies and practices that are likely to narrow gaps in achievement need to be broad and comprehensive to check inequality at the outset of a child's academic career and create conditions in which every child can flourish, achieve, and attain in school and in life. (Contains 56 footnotes, 26 figures and 2 tables.) [For "Parsing the Achievement Gap: Baselines for Tracking Progress. Policy Information Report," see ED482932.]