Which design is also referred to as a within-subjects ANOVA?

The repeated measures design is correctly identified as a within-subjects ANOVA because it involves taking multiple measurements from the same subjects under different conditions. This approach allows researchers to control for individual differences, as each participant serves as their own control across the different treatments or conditions.

In repeated measures designs, the analysis examines the differences in the dependent variable that can be attributed to the various levels of the independent variable while accounting for the variations among participants. This design is powerful for detecting effects since it reduces error variance related to individual differences, enhancing the sensitivity of the statistical tests used to analyze the data.

Unlike the other options, which involve different approaches to study design, the repeated measures design specifically focuses on observing the same subjects multiple times. Factorial ANOVA examines the interaction between two or more independent variables, but it may include between-subjects factors. A between-subjects design involves different participants in each condition, which does not align with the within-subjects concept. Single-factor ANOVA can be either between-groups or within-subjects, but it does not necessarily imply multiple measurements from the same subjects. Thus, repeated measures design aligns best with the concept of a within-subjects ANOVA.