DEVELOPMENT OF THE PERFORMANCE OF PROCESS SKILLS (POPS) TEST FOR MIDDLE GRADES STUDENTS

Abstract

The purpose of this project was to construct a valid and reliable non-curriculum-specific measure of integrated science process skills intended for use with middle school students. The major efforts in test development were focused on the refinements and modifications of the set of objectives and test items assessed by the existing Middle Grades Integrated Science Process Skills Test (Cronin and Padilla, 1986). Each objective and item was carefully analyzed to ensure that it was a valid representation of the intended process skills. Skills associated with planning, conducting, and interpreting results from investigations were delineated, and six objectives encompassing these skills were identified. Twenty-one items judged to be the best measures of these objectives were chosen for inclusion in the test. Modifications were made on the items in order to provide additional explanation for specific terms, i.e., the manipulated, responding, and controlled variables. The POPS test was constructed in order to assess the process skills dealing with identifying experimental questions (three items), identifying variables (six items), formulating hypotheses (three items), designing investigations (three items), graphing data (three items), and interpreting data (three items). The readability of the test was assessed using the FOG index, and the average grade level index of 6.8 was obtained. To establish content validity, objectives and items were submitted to a panel of reviewers. The responses of the four experts were consistent on almost all items in terms of indicating the correct answer and keying to a process skills objective. This concurrence of reviewers was taken as evidence of content validity and objectivity of scoring. To examine test reliability and item indices, the POPS test was administered to middle school students in grades six through eight. A total of 1,402 students were involved in this field test. Total scores on the 21-item test for overall students ranged from 1 to 20 (Mean = 9.8, S.D. = 4.2). Total test reliability (KR-20) was .75. Item difficulty indices ranged from .28 to .79 with an average of .47. Item discrimination indices obtained by using the upper 27% and lower 27% of the sample group showed that 20 of the 21 items were above .30 with an average of .49. Point biserial. correlation indices of item discrimination showed that 19 of the 21 items were above .30 with an average of .41. Each of these indices fell well within the acceptable range for a reliable test. These results provide evidence of the reliability and validity of the test. The POPS test is a reliable instrument for diagnostic and/or summative assessment in science classes or re- search studies. The test may be a useful means in classroom-based research, evaluation of instruction and learning, and curriculum validation in evaluation as well as assessing process skills competence of middle school students.