CMIT 321 FINAL EXAM PRACTICE QUESTIONS
AND ANSWER KEY 2026
◉ Tom Rogers 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"). He used the singalong method in his first period
class. His sixth period students continued solving math problems
with the old method. At the end of the term, Mr. Rogers found that
the first period class scored significantly lower than the sixth period
class on a mathematics achievement test. He concluded that the
singalong method was a total failure. Answer: 1. What are the
independent variable (including its levels) and the dependent
variable in this study?
Answer:
IV: Teaching method (singalong vs. traditional)
DV: Scores on the mathematics achievement test
2. What type of design and assignment procedures were used in this
study?
Answer:
Repeated measures
,3. Can you identify one or more threats to internal validity in this
experiment?
• Time of day is the most obvious confounding variable.
o Either the students or the teacher (or both) may be unprepared for
singing first thing in the morning.
o Students may find it difficult to pay attention first thing in the
morning. o The teacher may be less alert and less engaging at that
hour.
• Use of a non-equivalent control group.
o More remedial students may be assigned to mathematics during
first
period while a higher proportion of gifted students may be assigned
during sixth period.
o Truancy may be more prevalent during first period .
4. How could the experimenter redesign the study to address these
problems?
• Use a pretest/posttest design.
• Run the experiment on multiple classes meeting at different times
of day.
,• Have multiple teachers run the same experiment.
◉ 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.
Answer: 1. What are the independent variable (including its levels)
and the dependent variable in this study?
IV: Number of incoming flights the controllers handled
DV: Number of errors made by the controllers
2. What type of design and assignment procedures were used in this
study?
Answer: Repeated measures
, 3. What are some potential problems with this experimental design
and the procedures used?
➢ The introduction of additional incoming flights is confounded
with time and (potentially) fatigue.
o With the linear increase in number of flights, there may be a
practice effect.
Increases and decreases in number of flights is more random in
reality.
There may be a problem with ecological validity and therefore,
generalizability.
Fatigue may reduce the number of flights that controllers can handle
during the second half of the hour.
4. What are some ways that the design and procedures could be
revised to address these problems?
AND ANSWER KEY 2026
◉ Tom Rogers 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"). He used the singalong method in his first period
class. His sixth period students continued solving math problems
with the old method. At the end of the term, Mr. Rogers found that
the first period class scored significantly lower than the sixth period
class on a mathematics achievement test. He concluded that the
singalong method was a total failure. Answer: 1. What are the
independent variable (including its levels) and the dependent
variable in this study?
Answer:
IV: Teaching method (singalong vs. traditional)
DV: Scores on the mathematics achievement test
2. What type of design and assignment procedures were used in this
study?
Answer:
Repeated measures
,3. Can you identify one or more threats to internal validity in this
experiment?
• Time of day is the most obvious confounding variable.
o Either the students or the teacher (or both) may be unprepared for
singing first thing in the morning.
o Students may find it difficult to pay attention first thing in the
morning. o The teacher may be less alert and less engaging at that
hour.
• Use of a non-equivalent control group.
o More remedial students may be assigned to mathematics during
first
period while a higher proportion of gifted students may be assigned
during sixth period.
o Truancy may be more prevalent during first period .
4. How could the experimenter redesign the study to address these
problems?
• Use a pretest/posttest design.
• Run the experiment on multiple classes meeting at different times
of day.
,• Have multiple teachers run the same experiment.
◉ 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.
Answer: 1. What are the independent variable (including its levels)
and the dependent variable in this study?
IV: Number of incoming flights the controllers handled
DV: Number of errors made by the controllers
2. What type of design and assignment procedures were used in this
study?
Answer: Repeated measures
, 3. What are some potential problems with this experimental design
and the procedures used?
➢ The introduction of additional incoming flights is confounded
with time and (potentially) fatigue.
o With the linear increase in number of flights, there may be a
practice effect.
Increases and decreases in number of flights is more random in
reality.
There may be a problem with ecological validity and therefore,
generalizability.
Fatigue may reduce the number of flights that controllers can handle
during the second half of the hour.
4. What are some ways that the design and procedures could be
revised to address these problems?
