Imagine that you are a sports psychologist interested in the usefulness of a new visualization technique that has been developed for Olympic divers. You have decided to conduct an experiment to determine if the technique is effective. Discuss the importance of each of the following in regard to the experiment you are designing: Population Sample Hypothesis Independent variable Dependent variable Operational definitions Control group Random assignment Replication The student must make clear that the population is the group of individuals that the participants are drawn from, in this case, the population is Olympic divers (or some subset of Olympic divers). The student must recognize that the sample is the group of Olympic divers that is selected for this experiment. The sample must be random so the results of the experiment can be generalized to the population. The student must explain that the hypothesis is the statement of expectation about the outcome of the experiment. In this case, the hypothesis is that the new visualization technique will produce better dives. The student may state the null hypothesis, such as: “There is no difference between groups of Olympic divers.” Students must state the hypothesis for this particular experiment; a basic definition of “hypothesis” alone should not earn the point. The student must be aware that the independent variable is the variable manipulated by the experimenter. In this case, the IV is whether or not a diver is taught the new visualization technique. Students must state the independent variable for this particular experiment; a basic definition of “independent variable” alone should not earn the point. The student must be aware that the dependent variable shows the effect of the independent variable. In this case, the dependent variable is the quality of the dives. Again, students must state the dependent variable for this particular experiment to earn the point. To earn this point, the student must explain exactly how the dependent variable will be measured. The clearest way to do this is with diving scores. The student must explain the need for a group to which results of the visualization group may be compared. In this case, the control group would be a similar group of divers that is not trained in the new technique. The student must understand the importance of randomly assigning participants to the visualization and control groups. This allows the experimenter to assume that the only difference between the divers in the two groups is whether or not they are taught the visualization technique. The student must explain that experimental results are not fully accepted until the experiment is repeated. If the experiment cannot be replicated, the results were probably caused by chance instead of by the independent variable.