Question

Suppose that Ken teaches two sections of a course in kinesiology down at Kommunity Kollege. Ken teaches a day section of the course and an evening section of the course, both on Tuesdays and Thursdays. Ken wants to know if teaching with whimsical hand puppets can increase student learning. Ken decides to teach his day section with hand puppets and his evening section without hand puppets for the entire semester. When Ken created his syllabus, he forgot that he was scheduled to attend the Kinesiology Konference during the third week of the semester, so he had to cancel a week of lectures and fell behind on the course material. Oh, and then partway through the semester, a pandemic strikes, causing widespread illness, crippling world economies, and forcing Ken to give all of his remaining lectures online sitting at a card table in his frigid basement. During the online lectures, Ken is able to illuminate his basement with daylight through the windows during the day section but Ken has to use lamps for illumination during the evening class. Ken gives his lectures online but also records them for students who want to watch them again later. Ken is such a klutz with Zoom that the sound on his first week of online lectures does not get recorded properly and all the video recordings for the first week of online lectures are silent, with no audio. At the end of the semester, Ken gives the students what most people would call a test but what Ken calls a “Kommencement Kwiz”. Ken finds that the Kommencement Kwiz scores of the puppet group are significantly higher than the scores of the no-puppet group.

1.  (4 points) What is the independent variable?

2.  (4 points) What is the dependent variable?

3.  (4 points) Are the lectures that Ken had to cancel to attend the Kinesiology Konference a confound?  Why or why not?

4.  (4 points) Is the time of day of the lectures a confound?  Why or why not?

Answer 1

The study here was to study if the use of the hand puppets can increase student learning. For this purpose, the students are either taught with puppets or without puppets. And the metric used for student learning is their score in the Kommencement Kwiz.

1. The Independent variable is the one that is under the control of the experimenter. The experimenter varies the independent variable to see if it produces the desired effect. Hence the independent variable here is the use of puppets. This variable can belong to one of the two categories: use of puppet, no use of puppet. Hence this variable is a categorical variable.

2. The dependent variable is the one that the experimenter measures. The dependent variable is not in the control of the experimenter. The values assumed by the dependent variable vary depending on the changes in the independent variable. Therefore, the dependent variable here is the score of the students in the Kwiz.

A confound or a confounding variable is the one that influences both the dependent and independent variables. This can result in the relation between the variables that were not already present between them.

3. The canceling of the lectures due to Kinesiology Konference is not a confound. It did impact the schedule, but it did not impact the puppet and non-puppet groups differently. Hence it did not impact the independent variable. Also, there is no impact of this on the quiz score.

4. The time of the day of the lectures is a confound. The lecturer cannot manage the issue of light for the puppet and non-puppet groups. Hence, changing the timing of the lectures is going to impact the independent variable. Also, this will how easily the students can understand the lecture and hence it impacts the dependent variable.