Problem: ''An example of a research design that would call for repeated measures ANOVA would be the relationship between caffeinated beverages and positive mood. The research question would be: "What caffeinated beverage positively affects mood the most?" The independent variables would be coffee, tea, and soda. The dependent variable would be the participant's mood. Participants would fill out a questionnaire about their mood before consuming the drink and one hour after. The study would take three days to complete. The participants would drink one option each day and complete the questionnaire before and after.
This research question could be answered using a between-subjects design by restricting three groups to one independent variable. For example, group 1 would only drink coffee, group 2 would only drink tea, and group 3 would only drink soda. The data collected from the three groups would be compared and analyzed to determine which caffeinated beverage promotes a positive mood the most."