Affects on ITBS math and reading results: An analysis of the effect of school type and grade level on the ITBS math and reading results over a period of four years

The acceptance of charter schools as an alternative to conventional public schools brings to the forefront the lack of research available to confirm the effectiveness of charter schools. The study used individual level test results from the IOWA Test of Basic Skills (ITBS) math and reading data set to compare charter schools to conventional public schools and to study the potential of value-added as an accountability model. The basis of the value-added approach is to compare an individual's test result on one test to that of another to determine the individual's academic growth. The ITBS data included math and reading test results for Chicago Public Schools students in grades fifth through eighth, for the 2002 through 2005 school years. The study population consisted of 4,314 students, of which 1,449 were from charter schools and 2,865 from conventional public schools. The results indicated that reading and math performance was significantly higher in charter schools than in conventional public schools. Second, reading and math results were dependent on grade level but not on school type. Meaning the grade effect was significant however, the school type did not moderate the effect of grade level on reading and math performance. Third, the value-added approach showed the scores over time, as a function of school type, did not have an effect on reading and math scores. Reading and math performance however, varied over time, irrespective of school type. Overall student performance in both math and reading were significantly higher in charter schools, but there were no differences in academic growth, comparatively by school type. The results and recommendations for future studies emphasize the contributions of a longitudinal design in educational research and examination of the potential for the value-added approach.