Dietz and Henrich (2014) were interested in the impact of te…

Dietz and Henrich (2014) were interested in the impact of texting on student learning. A group of 99 college students were randomly assigned to text (N = 50) or not text (N = 49) during a prerecorded psychology lecture. At the end of the 20-minute lecture, students answered a 17-question quiz about the material that had just been presented. Which statistical test should the researchers use to analyze their data?

Twenty-five college students experience the effects of alcoh…

Twenty-five college students experience the effects of alcohol on reaction time. They perform very basic timed responses in a driving simulator both before and after consuming several alcoholic beverages. The researcher collects a reaction time result for each of the 25 students before and after intoxication, for a total of 50 measures. What are the degrees of freedom for this study?