Question

research methods for the behavioral sciences 5th edition pdf Chapter 11

1. In this diagram response time is measured after intace of alchol or no alcohol. The researchers also wanted to see if there could be a possible interaction effect of caffeine. Describe possible main- and interaction effects.

2. For a two factor design with three levels of factor A and two levels of factor B, how many participants are needed for each of the following situations in order to obtain 10 scores for each treatment condition?

A. Both factors are between subjects

B. Both factors are within subjects

C. Factor A is between subjects and factor B is within subjects

Answer 1

1. When a study analyses the main effects, it measures the mean differences among the levels of one independent variable (IV) on the dependent variable. In this case, the researchers can measure the main effects of alcohol consumption (IV 1) on response time (DV) and caffeine consumption (IV 2) on response time (DV). In case of interaction effects, the researchers would analyse if levels of one independent variable impact how the levels of the other independent variable affect the dependent variable. That is, if different levels of alcohol and caffeine consumption combine to affect response time.

Please post the other question separately.

2.