Author Question: An experimenter collected data on how well a study guide improved grades on an exam taken late in ... (Read 111 times)

Cooldude101 · **on:** Jun 20, 2018

An experimenter collected data on how well a study guide improved grades on an exam taken late in the semester compared to an exam taken early in the semester. Using a related sample means t test, the results showed that later grades were higher than early grades (t(74) = 3.64, p < .05). Which of the following was NOT an advantage of this design?

a. The design controlled for students who did poorly both times.
b. The design controlled for extraneous variables like intelligence levels.
c. The design controlled for carry-over effects from already having taken one exam when the second exam was administered.
d. All of the above are advantages of this design.

Question 2

The difference between the values of degrees of freedom for one sample t tests and related means t tests is that

a. related means t tests have a df = N 2, where N is the number of pairs of scores.
b. related means t tests have a df = N, where N is the number of pairs of scores.
c. related means t tests have a df = N 1, where N is the number of pairs of scores.
d. one sample t tests have a df = N 2, where N is the total number of raw scores.