desk and man.jpg Recently I read an Education Week article previewing a book, The Secret of TSL, by management expert William G. Ouchi, which lays out the case why the key to improving student achievement is lightening teaching loads. In his new book, Ouchi defines TSL (total student load) as the number of students that teachers encounter each academic term and the number of papers they grade. In his study of 442 schools in eight large urban districts that have devolved power to local principals Ouchi finds that these schools have reduced TSL in measurable ways. Additionally, these schools tend to have higher passing rates on state exams. Ouchi argues that lowering TSL increases the likelihood that a student will have more informal contact with their teachers and that will motivate the student to keep on going, which is different than simply reducing class sizes. Ouchi’s study provides new quantitative evidence suggesting how much lower teaching loads might matter for schools. The study also deepens the debate on school decentralization, where school districts transfer power to local principals. The study found that local principals empowered by this new authority often take steps to lower teaching loads. They hire more teachers, eliminate support staff such as front office attendants and roll social studies and English classes into an integrated humanities class. While prominent education leaders such a New York City Schools Chancellor Joel I. Klein and current U.S. Secretary of Education Arne Duncan have embraced the idea, decentralization as a strategy has produced mixed results. Decentralization was deemed successful in the 80,000-student Edmonton Canadian school system, yet it has provided mixed results in the Chicago school district. Study skeptics also argue that Ouchi overvalues management and underemphasizes content and teaching methods in his work. Studies such as Mr. Ouchi’s are helpful in the debate on how to improve education outcomes. However, these studies should always be taken in context. Ouchi’s study examined exclusively urban districts, which means that the study’s results are not necessarily applicable to rural and suburban districts. Questions must also be asked about the demographic and socioeconomic of the cases Ouchi was studying. At The Improve Group, emphasis on scope of these studies are utterly important. Future work in evaluating education policies should strongly consider these issues before making policy decisions. I would appreciate comments on these topics.