All teachers do assessments. Biology teachers, by grading exams, quizzes, papers, and lab reports, assess mostly "knowledge." An important part of being a modern biologist, however, is the ability to perform certain technical or manual skills (known in the trade as "techniques") such as running gels, pipetting, recording from excitable cells with microelectrodes, performing tissue culture, and the like. In this article, the author describes a rubric intended to help measure a student's ability to use the compound light microscope. The rubric is designed simply to assess the ability to use a compound, binocular, light microscope. The mechanics of administering the assessment and scoring the student's performance are also discussed. (Contains 2 figures.)