Question

An experimenter wants to investigate the accuracy of fortune-tellers' predictions. She asks fifteen fortune-tellers and fifteen students, to make ten specific predictions about what will happen to her in the next month. She then records, for each of these groups of people, how many of the predictions come true.

1. What are the variables of interest in this study? If the study is an experimental one, identify which variable is the IV and which variable is the DV.

2. What do you think the researcher's hypothesis was?

3. Based on your answer to B, what should the null and alternative hypotheses be?

4. Based on your answer to B, which statistical test would you use to address this hypothesis? Explain your reasoning.

Answer 1

1. What are the variables of interest in this study? If the study is an experimental one, identify which variable is the IV and which variable is the DV.

The IV in the study would be professional background.

The DV in the study would be accuracy of predictions.

2. What do you think the researcher's hypothesis was?

The researcher’s has probably hypothesized that there is no significant differences in the accuracy of predictions made by fortune tellers and students.

3. Based on your answer to B, what should the null and alternative hypotheses be?

H0: There is no significant differences in the accuracy of predictions made by fortune tellers and students.

H1: There is a significant differences in the accuracy of predictions made by fortune tellers and students.

4. Based on your answer to B, which statistical test would you use to address this hypothesis? Explain your reasoning.

For this study, I would use a two sample t test as the intention is to study if there are any significant group differences between fortune-tellers and students in their accuracy of predictions, by comparing the mean scores for each group.