New nationwide data collected by the U.S. Department of Education's civil rights office reveal stark racial and ethnic disparities in student retentions, with black and Hispanic students far more likely than white students to repeat a grade, especially in elementary and middle school. The contrast is especially strong for African-Americans. In the most extreme case, more than half of all 4th graders retained at the end of the 2009-2010 academic year--56 percent--were black, according to the data, which account for about 85 percent of the nation's public school population. In 3rd grade, 49 percent of those held back were black. Those findings come even though African-American students represented less than one-fifth of the entire universe of students in the K-12 data set collected from districts. In all, nearly 1 million students, or 2.3 percent of those enrolled, were retained across K-12, the data show. Black students were nearly three times as likely as white students to be retained, when combining all grade levels. Hispanic students were twice as likely to be held back. The new Civil Rights Data Collection, a portion of which was provided to "Education Week," was scheduled for public release on March 6. Collected from nearly 7,000 school districts, the data are part of an ongoing information-collection effort by the agency's office for civil rights. In this latest round, the agency significantly expanded the type of information gathered, for the first time collecting school-by-school retention data. Experts were quick to note that although the racial and ethnic disparities in retention are alarming, they are generally consistent with an abundance of prior research at the state and local levels, and have a strong correlation to achievement gaps in the United States. Another area of the federal data examined by "Education Week" was coursetaking and passing rates in Algebra 1. The data suggest that disproportionately low numbers of black 7th and 8th graders take introductory algebra. Meanwhile, about one-quarter of all 9th and 10th graders failed algebra, the data show, with higher failure rates for black and Hispanic students than for whites and Asians. Several researchers urged caution in interpreting algebra pass-fail rates, noting that the rigor of algebra courses varies widely and that some schools may be overly generous in giving a passing grade.