The focus of this study was to evaluate one problem-solving experiment in the Wisconsin Performance Assessment according to the criteria I established in the literature review. Data was gathered from each student performing this task using a protocol analysis. In these tape recorded sessions students were encouraged to think aloud while problem solving, and their procedures were observed. Three students from Deanne`s fifth grade classroom were selected to take this test (one girl and two boys, representative of the class ratio). Each session lasted approximately 45 minutes to one hour depending on the students` rate of work. Although this experiment appears to need refinement, this assessment, in this study, is a positive step in the right direction. It is evident that the test makers have taken current research ideas into consideration when creating this task. Another strength of this test is in how the test is viewed by the test develop in `doing science` through the years. The result from this test may be quite fruitful in curriculum design and student evaluation in science.