When using a pretest-posttest nonequivalent groups design to evaluate a new teaching method across two different classrooms, what remains a primary concern regarding potential confounding variables?

In a study evaluating a new method for teaching fractions by comparing two different third-grade classrooms, match each component of the research design with its role or description.

A researcher is evaluating a new 'Fraction Pizza' teaching tool using two existing third-grade classrooms. To improve upon a posttest-only comparison, the researcher decides to measure and compare student improvement from a baseline. Arrange the following steps in the correct chronological order to properly execute this research approach.

In the fraction teaching example, if a researcher finds that the treatment group improved by 30 points while the control group improved by only 5 points, they can definitively conclude that the 25-point difference was caused by the new teaching method because the pretest scores were used to account for initial differences in ability.

Imagine you are an instructional designer tasked with constructing a research study to evaluate a new 'Fraction Pizza' software using two existing third-grade classrooms. To synthesize a plan that improves upon a posttest-only approach by comparing the magnitude of improvement across the two classrooms, which combination of research steps should you propose?

In the teaching fractions example of a pretest-posttest nonequivalent groups design, the control classroom only takes the final posttest, while the treatment classroom takes both the baseline pretest and the final posttest.

In the fraction teaching study, a researcher concludes that the new instructional method is the sole reason for the treatment group's higher scores. To critically evaluate the validity of this claim, the researcher must identify that _____, such as differences in teaching styles, remain as plausible alternative explanations for the observed improvement.