Assignment 3 Part 1 Experimental Design
1. Read through the scenario and answer the questions. A sample problem is provided below.
An airport administrator investigated the attention spans of air traffic controllers to determine how many
incoming flights the average controller can coordinate at the same time. Each randomly selected controller was
tested, without his or her knowledge, by a computer program that fed false flight information to a computer
terminal. The controller first “received” information from one plane, and by the end of an hour the controller was
coordinating 10 planes simultaneously. The administrator analyzed the errors collected by the computer
program. The analysis revealed that the maximum number of planes a controller could handle without making
potentially fatal errors was six planes. Also, no errors occurred when only one to three planes were incoming.
He concluded that a controller should never coordinate more than six incoming flights.
a. Identify the explanatory variable(s)/ independent variable(s). Identify any treatment and control groups.
b. Identify the response variable/ dependent variable(s).
c. Identify any confounding variable(s).
d. Propose a method to “unconfound” the experiment.
e. Discuss any ethical considerations the experimenter made in this study.
Sample Solution:
Mrs. Quincy wanted to test a new “Singalong” method to teach math to fourth graders (e.g., “I love to multiply” to the
tune of “God Bless America”). She used the Singalong method in his first period class. Her sixth period students
continued solving math problems with the old method. At the end of the term, Mrs. Quincy found that the first period
class scored significantly lower than the sixth period class on a mathematics achievement test. She concluded that
the Singalong method was a total failure.
a. Identify the explanatory variable(s)/ independent variable(s). Identify any treatment and control groups.
Use of the Singalong method (treatment) or the traditional method (control group)
b. Identify the response variable/ dependent variable(s).
The scores achieved on the math tests by the usage of either method.
c. Identify any confounding variable(s).
Time of day (the 1st period may have done worse since it was earlier in the day)
Previous student knowledge/ preparation (6th period may have been stronger at math from the start)
d. Propose a method to “unconfound” the experiment.
2 morning classes participating in the study, and a random assignment is given out, checking the student outcomes
after 1 period OR two 1st period classes participate and switch instructors.
2. Research in Business: Designing an Experiment, Worker Productivity in Open Workspaces
Open workspaces have become widely popular among many businesses today. (We have them at Hult!) The
suggested benefits of having open workspaces include an increase in worker productivity and creativity, team
collaboration, and employee happiness at work.
Design a study in which you test the relationship between worker productivity and open workspaces. Do open
workspaces really create more productive work environments for employees? Create and identify your
explanatory and response variables. Explain why the variables you chose are the best tools for measurement
in this experiment. Describe your experimentation process in full detail. Identify and confounding/lurking
variables that your experimental design accounted for and also any that might remain further explored. If
applicable, create a diagram showing your experimental design.