Connecticut is developing a new grade 10 statewide testing program known as the Connecticut Academic Performance Test (CAPT). The CAPT reflects the changing nature of standardized assessment by using a variety of assessment formats including performance tasks, open-ended questions, and multiple-choice tests. This paper describes the research that was conducted during the development of the CAPT Science assessment, which includes a performance component. In the design, students are given a hands-on laboratory activity during a 4-week window before the written portion of the test, which then includes some questions on the performance task. The laboratory reports on the performance task are scored only by teachers, and not at the state level. Five performance tasks were developed, and each was completed by nearly 2,000 tenth graders. Approximately 6,000 students responded to follow-up questions without completing the task and thus served as a control group. Results support the feasibility of moving the performance task out of the assessment and into the classroom while maintaining a meaningful link between the two. Four tables and one figure present findings from the pilot studies. Four appendixes contain one task, follow-up questions, and scoring rubrics for each. (Contains 4 references.) (SLD)