The article discusses different ways to analyze pretest-posttest designs in research. It explains why using ANCOVA is usually better than other methods like one-factor ANOVA or two-factor ANOVA. By using the pretest as a covariate and the posttest as the dependent variable, ANCOVA can adjust for chance differences on the pretest and generally has higher power. This approach helps researchers better understand the relationships between variables and make more accurate conclusions in their studies.