Question

Subjects in the weapon condition were only slightly, but not significantly, less accurate than controls on the 20-item questionnaire. Weapon present subjects were correct on 45.8% of the items, while control (weapon absent) subjects were correct on 50.3% of the items, t(34) = 1.37, p > .05, one tailed.

1. What kind of study design is this (experimental or correlational)?

2. If experimental, what is the independent variable?

3. If experimental, what is the dependent variable?

4. What kind of statistical test did the author run, and how do you know the used this test?

5. What do you think the null and alternative hypotheses are in this study? You might have to guess, but make it an educated guesses!

Answer 1

1. The study is an experimental design. This is because there is an indication of a control condition, a characteristic feature of experiments.

2. The independent variable is weapon presence.

3. The dependent variable is response accuracy. (What the questionnaire is measuring is not mentioned here)

4. A t test was used here to obtain the results. This is because differences between the two experimental conditions are compared. The results also report the value of the t statistic.

5. Null hypothesis: Weapon presence has no significant impact on response accuracy.

Alternative hypothesis: Weapon presence has a significant impact on response accuracy.