Which of the following scenarios can be appropriately answered using a Two-Way ANOVA test?

• A. Researchers compare final exam scores between students who attended tutoring vs. who did not
• B. A psychologist compares anxiety levels among patients receiving one of two treatments
• C. A nutritionist studies how meal type (breakfast, lunch, dinner) and diet plan (low-carb, low-fat, Mediterranean) affect blood sugar levels
• D. A professor tests if average scores on a quiz are significantly different between 5 class sections

Answer: (C)

Verified step by step guidance

1. Understand that a Two-Way ANOVA is used when you want to examine the effect of two independent categorical variables (factors) on one continuous dependent variable, as well as any interaction effect between these two factors.
2. Identify the factors and levels in each scenario: For example, in the nutritionist's study, the two factors are 'meal type' with 3 levels (breakfast, lunch, dinner) and 'diet plan' with 3 levels (low-carb, low-fat, Mediterranean). The dependent variable is blood sugar level, which is continuous.
3. Check if the other scenarios involve two factors: The tutoring scenario has only one factor (tutoring vs. no tutoring), the psychologist's study has one factor (type of treatment with two levels), and the professor's study has one factor (class sections with five levels). None of these have two factors.
4. Conclude that only the nutritionist's study fits the criteria for a Two-Way ANOVA because it involves two categorical independent variables and one continuous dependent variable.
5. Remember that Two-Way ANOVA also allows testing for interaction effects between the two factors, which is an important advantage over One-Way ANOVA.