This paper presents a study conducted with two goals in mind: (1) to employ an operational definition of school choice that is more faithful to orthodox choice theory than are extant definitions; and (2) with this definition, to assess possible effects of school choice on students' academic commitment and achievement. Claims for the positive effects of school choice on student achievement deserve serious scrutiny because of increasingly widespread support for school-choice initiatives. Proponents for school choice believe that choice results in a better match between the student and the school, which, in turn, should result in greater academic commitment and academic achievement. To date, however, the research regarding the results of school choice is inconclusive. The definition of school choice captures these three elements: (1) school choice involves a public-school student selecting another public school; (2) school choice requires active selection from among perceived alternatives; and (3) school choice effects will be greater when the chosen school presents itself as a magnet school or "school of choice." The paper details the methodology of the study, including data sources, dependent and independent variables, and outcomes. The results indicate that school choice had no effect on students' subsequent academic commitment or academic achievement. Contains 23 references. (RJM)