Graph 1. Linearity between covariant and dependent variable
As seen in the graph, there is a linear relationship between covariant
(pre-test) and dependent variable (post-test) In addition, the R square
results showed that 37% of the posttest scores of the experimental
group were due to the pre-test scores, and that the change in the 55%
of the posttest scores in the control group was due to the pre-test
scores. Finally, in order to make ANCOVA, the homogeneity of the slope
between the regression lines must be tested. In fact, it is seen that
the slopes are not very different from each other. This shows that we
can do ANCOVA. however, when we look at the relationship between the
slopes statistically, there is no significant difference between the
slopes.