The study is based on an analysis of National Assessment of Educational Progress (NAEP) tests given between 1990 and 1996. The authors rank the 44 participating states by raw achievement scores, by scores that compare students from similar families, and by score improvements. They also analyze which policies and programs account for the substantial differences in achievement across states that can't be explained by demographics. Here are the key findings:

• Math scores are rising across the country at a national average rate of about one percentile point per year, a pace outstripping that of the previous two decades and suggesting that public education reforms are taking hold. Progress is far from uniform, however. One group of states--led by North Carolina and Texas and including Michigan, Indiana and Maryland--boasts gains about twice as great as the national average. Another group--including Wyoming, Georgia, Delaware and Utah--shows minuscule gains or none at all. Most states fall in between.

• Even more dramatic contrasts emerge in the study's pathbreaking, cross-state comparison of achievement by students from similar families. Texas heads the class in this ranking with California dead last. Wisconsin, Montana, Iowa, Maine, North Dakota, Indiana and New Jersey cluster closely behind Texas. Louisiana, Mississippi, West Virginia, Alabama and Rhode Island perform almost as dismally as California.

• Although the two states are close demographic cousins, Texas students, on average, scored 11 percentile points higher on NAEP math and reading tests than their California counterparts. In fact, the Texans performed well with respect to most states. On the 4th-grade NAEP math tests in 1996, Texas non-Hispanic white students and black students ranked first compared to their counterparts in other states, while Hispanic students ranked fifth. On the same test, California non-Hispanic white students ranked third from the bottom, black students last, and Hispanic students fourth from the bottom among states.

• Differences in state scores for students with similar families can be explained, in part, by per pupil expenditures and how these funds are allocated. States at the top of the heap generally have lower pupil-teacher ratios in lower grades, higher participation in public prekindergarten programs and a higher percentage of teachers who are satisfied with the resources they are provided for teaching. These three factors account for about two-thirds of the Texas-California differential. Teacher turnover also has a statistically significant effect on achievement. (California is now implementing class-size reduction and other reforms but these steps began after the 1996 NAEP tests.)

• Having a higher percentage of teachers with master's degrees and extensive teaching experience appears to have comparatively little effect on student achievement across states. Higher salaries also showed little effect, possibly reflecting the inefficiency of the current compensation system in which pay raises reward both high- and low-quality teachers. However, the report points out that salary differences may have more important achievement effects within states than between states. Also, they may have greater impact during periods when teachers are in shorter supply than during the 1990-1996 measurement period.

• To raise achievement scores, the most efficient and effective use of education dollars is to target states with higher proportions of minority and disadvantaged students with funding for lower pupil-teacher ratios, more widespread prekindergarten efforts, and more adequate teaching resources. As for teacher salaries and education, the report adds, "efforts to increase the quality of teachers in the long run are important, but ... significant productivity gains can be obtained with the current teaching force if their working conditions are improved."

• The most plausible explanation for the remarkable rate of math gains by North Carolina and Texas is the integrated set of policies involving standards, assessment and accountability that both states implemented in the late 1980s and early 1990s.

The RAND study, led by David Grissmer, is based on NAEP tests given in 1990, 1992, 1994 and 1996 to representative samples of 2,500 students from the 44 voluntarily participating states. Five tests were given in mathematics and two in reading at either the 4th- or 8th-grade level. Not all of the states took all of the tests. And there were too few reading tests to permit a separate analysis of those results. Taken together, however, the tests provided the first set of data permitting statistically valid achievement comparisons across states. The researchers used data from the census and from the National Educational Longitudinal Survey to establish the student samples' family characteristics.

The 1998 NAEP reading and math scores became available too late to be incorporated in this analysis. "We're examining those data now, however, and we find that the state rankings change little and our findings about which policies make the most difference aren't affected at all," Grissmer declares.

"Our results certainly challenge the traditional view of public education as 'unreformable'," he concludes. "But the achievement of disadvantaged students is still substantially affected by inadequate resources. Stronger federal compensatory programs are required to address this inequity."

Grissmer's coauthors include Ann Flanagan, Jennifer Kawata and Stephanie Williamson. Improving Student Achievement: What State NAEP Test Scores Tell Us was supported by the ExxonMobil Foundation, the Danforth Foundation, the NAEP Secondary Analysis Program, the Center for Research on Educational Diversity and Excellence, and by RAND.

RAND is a nonprofit organization that helps improve policy and decisionmaking through research and analysis.