Extra Credit – No Penalty for Trying Suppose a researcher compares 4 groups (Freshmen, Sophomores, Juniors, Seniors) on the average number of steps taken per day, and finds an overall significant F-ratio. What is the logic of using post hoc methods like the Tukey method or Bonferroni method in making pairwise comparisons (why are these special methods needed)?

A researcher was interested in comparing 3 group conditions: Meditation, Progressive Relaxation, and a Control condition on heart rate. 28 freshmen undergraduates from USF were randomly selected.  From these 28 students, 13 were randomized to the Control Condition, 8 were randomly assigned to Meditation, and 7 were randomly assigned to Progressive Relaxation. What statistical technique would be used in this study?

A researcher was interested in comparing 3 group conditions: Meditation, Progressive Relaxation, and a Control condition on heart rate. 28 freshmen undergraduates from USF were randomly selected.  From these 28 students, 13 were randomized to the Control Condition, 8 were randomly assigned to Meditation, and 7 were randomly assigned to Progressive Relaxation. What would be the degrees of freedom for: Between groups df = _____  

For an independent samples t-test, list the 3 assumptions underlying the statistical test.

A researcher was interested in comparing the number of campus recreation visits during the semester for STEM/Science undergraduate majors versus non-STEM/Science undergraduate majors. From a computer database that had divided the undergraduate population into STEM/Science undergraduate majors and non-STEM/Science undergraduate major, the researcher randomly selected 100 STEM/Science undergraduate majors and randomly selected 100 non-STEM/Science undergraduate majors, and then obtained data records for the number of campus recreation visits during the Fall term. How many degrees of freedom would this statistical test have?

What type of hypothesis is the following: VO2 Max is not related to Running speed.

Extra Credit – No Penalty for Trying If a researcher has a nominal/categorical variable like Sport Participated In (Swimming, Basketball, Track, Soccer), what is meant when a researcher creates “dummy variables” to represent this variable?  What is a dummy variable?

A researcher was interested in evaluating an intervention that would impact body mass. The researcher was also interested in evaluating if there were sex differences in body mass. The researcher recruited 10 males and 10 females for the study. For the 10 males, 5 males were randomly assigned to the intervention and 5 males were randomly assigned to a control condition. Similarly, for the 10 females, 5 females were randomly assigned to the intervention and 5 females were randomly assigned to a control condition. Based on the information provided, what statistical technique produced the table above?

If a researcher was planning a randomized controlled trial to evaluate the effect of an exercise intervention (intervention group vs. control group) on blood pressure, in which situation would you need a larger sample size to achieve the same level of power.  Assume all other factors are kept the same.

Power can range from -1 to +1.