Although instructional technology has made large gains in the last 15 years in terms of the quantity and quality of computers available in schools, major questions remain about the effects of all this technology on student achievement. The author has conducted a series of studies to address these questions. By analyzing test score and questionnaire data from the National Assessment of Educational Progress (NAEP), he draws conclusions about the relationship between achievement and various instructional practices, including computer access and use. The analysis in this article focuses on 12th graders' achievement on the NAEP in U.S. history. The author finds that students who make more frequent use of computers for generic academic tasks--word processing, art projects, creating charts, tables, and graphs, and communicating through e-mail and chat groups--had higher achievement in history. He concludes that high schools will get the biggest boost to student achievement by ensuring that students have the basic technology skills they need to apply technology flexibly to learning tasks in their content-area courses. (Contains 1 figure.)