MA121: Introduction to Statistics

Question 1 out of 5.
Which of the following represent within-subjects variables?

Age: Subjects of four different ages were used in the experiment.

Trial: Each subject had three trials on the task and their score was recorded for each trial.

Dose: Each subject was tested under each of five dosage levels.

Day: Each subject was tested once a day for four days.

Intensity: Each subject was randomly assigned to one of five intensity levels.

Question 2 out of 5.
Differences among subjects in overall performance constitute a source of error for

between-subjects variables

within-subjects variables

Question 3 out of 5.
Sphericity is an assumption made in

between-subjects designs

within-subjects designs

Question 4 out of 5.
Violating the assumption of sphericity:

leads to a higher Type I error rate

rarely has a meaningful effect on the Type I error rate

decreases the Type I error rate

Question 5 out of 5.
Subjects were each tested under three conditions: quiet, noise, music. What is the F ratio in an ANOVA?

  quiet	  noise	  music

 49	 43	 80
 33	 56	 55
 39	 60	 77
 57	 41	 50
 69	 75	 60
 43	 50	 60
 40	 74	 79
 62	 49	 73
 60	 58	 57
 35	 65	 59