A study was conducted to investigate: (1) the relationships between the results from various forms of assessment and the patterns of correlation across content areas; (2) how cognitive components correlate with the test results from different classroom assessments; and (3) how content areas affected the relationships. Data were collected from a sixth-grade classroom of 40 students. Three assessment forms were administered crossing the two content areas of making neutral solutions and designing momentum experiments. The assessment forms were: (1) performance based assessment (PBA); (2) multiple choice (MC); and (3) short answer (SA). Findings were that MC and SA covaried more with one another than either did with PBA. Content area affected how PBA covaried with MC and SA. Deductive reasoning was the most obvious cognitive component that differentiated the designated content areas. This study demonstrated that PBA may not always be the best choice to measure students' cognitive capabilities. Paper and pencil tests may measure abstract relations as well as PBA does. (SLD)