Guidelines for use by school practitioners in assessing students' motivation to learn are presented. Most of the instruments reviewed and literature discussed pertain primarily to the academic motivation and achievement of students in kindergarten through grade 12. Most are paper-and-pencil, self-report, group-administered measures that can be given within an hour. Definitions of basic concepts, current issues for assessing motivation, and thoughts on the future of assessment of motivation are presented. Lengthy reviews of certain selected instruments are presented, along with shorter reviews of related instruments and criteria for selecting appropriate measures of motivation. The guide is designed to provide users with enough of a conceptual overview of motivation and an awareness of existing instruments to proceed in their own review and selection more efficiently and systematically. Appendices include reviews of motivation measures, multidimensional measures, and motivation-related measures; a checklist for selecting a motivation instrument; and lists of testing resources and pertinent bibliographies. (TJH)