Describe the number of factors, levels and conditions in this design and Explain what is meant by a main effect and an interaction effect: Applied Quantitative Methods Assignment, MMU, UK

Question 3.

A researcher was interested in whether the effectiveness of health messages interacts with the personality of the reader. The study used two types of messages: gain-framed and loss-framed. Gain-framed messages promote the health benefits of exercising, while loss-framed messages emphasize the health risks of not exercising. The researcher was interested in whether the effectiveness of the message frame is different for people with approach-oriented versus avoidance-oriented personalities.  People who are approaching-oriented tend to be more motivated by gaining rewards, while people who are avoidance oriented tend to be more motivated by avoiding harm. Participants were tested and classified as either approach-oriented or avoidance oriented. Each participant was randomly allocated to read either gain-framed or loss-framed messages. Their intention to exercise was then measured as the dependent variable.

1. Describe the number of factors, levels, and conditions in this design. Explain what is meant by the main effect and an interaction effect by referring to the main and interaction effects that could potentially be obtained in this design.
2. Graphs 3a & 3b show plots of hypothetical outcomes from this design. What does each graph suggest about the presence or absence of main effects and the presence and type of interaction (if any)? Refer to and describe the features of the graphs to support your answer.
3. Briefly identify an appropriate type of statistical analysis to use for this design and explain why it is appropriate.