Statistical Analysis
Student learning and the effectiveness of each method of instruction were
measured by examining the participants' pretest and posttest scores and then analyzing
them using statistical analysis. ANCOVA analysis was initially selected to test the
research question and related null hypothesis for the study. The results of the statistical
analysis, along with the accompanying post hoc analyses, provided a measurement of the
comparative effectiveness of CAI and TDA for teaching mathematics to high school
students with SLD. ANCOVA was chosen because of its relative advantage over other
statistical methods. It allows for the effectiveness of the method of instruction to be
analyzed while recognizing the impact of prior student knowledge as measured by
student pretest scores (i.e., the covariate).