In Chicago, where the school day is short, Marquette Elementary Principal Paul O’Toole did something unusual: He spent about $170,000 in grant money last year to extend the school day by one hour for middle-grade students, bringing their daily instructional time more in line with national norms.
Marquette’s experiment was not an instant success. Teacher assignments had to be shuffled, in part because the school departmentalized at 7th and 8th grade, and teachers had to master new lessons. Despite the additional learning time, test scores were flat in 2009: Marquette’s 6th- through 8th-graders scored below district averages on value-added measures (which compare a school’s gains on state achievement tests to demographically similar students elsewhere in the district)...