Scenario: Imagine you are a researcher who is interested in studying whether sleep deprivation leads to increased reaction times (i.e., being slower) when driving. You randomly select a sample of 30 licensed drivers. Fifteen participants are randomly assigned to get 5 hours of sleep for three consecutive nights. The other 15 participants are randomly assigned to get 8 hours of sleep for three consecutive nights. For the purposes of this Assignment, assume that all participants sleep exactly the required amounts. After the third night, all participants take a driving simulation test that measures their reaction times.
Reaction times in seconds for participants with 5 hours of sleep 0.82 0.84 0.76 0.9 0.66 0.86 0.72 0.86 0.86 0.74 0.77 0.93 0.9 0.88 0.84
Reaction times in seconds for participants with 8 hours of sleep 0.7 0.7 0.82 0.81 0.8 0.72 0.7 0.78 0.83 0.8 0.71 0.79 0.72 0.84 0.85
- Explain whether the researcher should use an independent-samples t-test or a related-samples t-test for this scenario. Provide a rationale for your decision.
- Identify the independent variable and dependent variable.
- Knowing the researcher believes that people who sleep less will have slower reaction times, state the null hypothesis and alternate hypothesis in words (not formulas).
- Explain whether the researcher should use a one-tailed test or two-tailed test and why.
- State the degrees of freedom and explain how you calculated it by hand.
- Explain whether the researcher should retain or reject the null hypothesis. Provide a rationale for your decision. Are the results statistically significant?
- Explain what the researcher can conclude about the relationship between amount of sleep and reaction times.