The purpose of this manual is to encourage discussions among science teachers about desired student outcomes in science and assessments appropriate to these outcomes. Once teachers know clearly what they hope to accomplish with their students, choosing appropriate assessment measures follows. Assessment methods described center on observing students informally or formally; asking students questions through interviews and self-assessments; and evaluating student work through open-ended questions, performance tests, portfolios, and other assessments. Chapters provide information and examples for the following topics: (1) current views on assessment; (2) desired student outcomes in science; (3) student assessment methods; (4) rubrics and grading; and (5) getting started. Twelve figures illustrate the discussion. An appendix discusses reform in curriculum and instruction. (Contains 28 references.) (SLD)