Deck 9: The Logic of Experimental Design

Question 1

To say that an experiment contains a confound means that

A)different subjects are assigned to each group.
B)the dependent variable is measured.
C)the independent variable is manipulated.
D)there is an uncontrolled extraneous variable in the experiment.

Answer 1

D

Question 2

When we can generalize from the sample used in a study to the population of interest we say that the study has _____ validity.

A)internal
B)external
C)construct
D)content

Answer 2

B

Question 3

When subjects are lost differentially from the experimental and control groups,any observed effect may be due to

A)mortality.
B)instrumentation.
C)diffusion of treatment.
D)history.

Answer 3

A

Question 4

Changes that occur naturally in the subjects,over time could result in the confound of

A)history.
B)maturation.
C)regression to the mean.
D)diffusion of treatment.

Question 5

In an experimental study of the effects of exercise on stress,stress is the

A)dependent variable.
B)independent variable.
C)control group.
D)experimental group.

Question 6

In an experimental study of the effects of exercise on stress,exercise is the

A)dependent variable.
B)independent variable.
C)control group.
D)experimental group

Question 7

Independent variable is to dependent variable as _____ is to _____.

A)measure; manipulate
B)manipulate; measure
C)control group; experimental group
D)experimental group; control group

Question 8

A limitation in the ability to differentiate between scores at the bottom of the scale is a _____ and a limitation in the ability to differentiate between scores at the top of the scale is a _____.

A)practice effect; fatigue effect
B)fatigue effect; practice effect
C)ceiling effect; floor effect
D)floor effect; ceiling effect

Question 9

Increasing the number of levels of the independent variable is to _____ replication as changing the type of dependent measure is to _____ replication.

A)exact; conceptual
B)conceptual; exact
C)systematic; exact
D)systematic; conceptual

Question 10

Using the same subjects in each condition in an experiment is to using different subjects in each condition in an experiment as _____ is to _____.

A)between-subjects design; within-subjects design
B)control group; experimental group
C)within-subjects design; between-subjects design
D)experimental group; control group

Question 11

Single-blind experiments help to control for ____ effects whereas double-blind experiments help to control for _____ effects.

A)participant; experimenter and participant
B)experimenter and participant; participant
C)fatigue; practice
D)practice; fatigue

Question 12

A decline in performance due to repeated testing is a(n)_____ effect and improvement in performance due to repeated testing is a(n)_____ effect.

A)instrumentation; mortality
B)mortality; instrumentation
C)practice; fatigue
D)fatigue; practice

Question 13

After grading 20 very poor term papers,Professor Jones was so upset by his students' writing that he became even more conscious of errors in their papers.Professor Jones' change in his grading criteria is similar to the confound of

A)mortality.
B)history.
C)instrumentation.
D)diffusion of treatment.

Question 14

In an experimental study of the effects of exercise on stress,subjects are randomly assigned to either the no exercise group or the exercise group.These groups represent the _____ and the _____,respectively.

A)independent variable; dependent variable
B)dependent variable; independent variable
C)control group; experimental group
D)experimental group; control group

Question 15

Baseline is to treatment as _____ is to _____.

A)dependent variable; independent variable
B)independent variable; dependent variable
C)control group; experimental group
D)experimental group; control group

Question 16

John conducted an experiment to test the effectiveness of a smoking cessation program.The experiment took place over a one-month time period.Participants in the control group and the experimental group (those who participated in the smoking cessation program)recorded the number of cigarettes that they smoked each day.John was unaware that "national stop-smoking week" also happened to take place during the one-month time period of his experiment.John's experiment is now confounded by

A)maturation.
B)history.
C)regression to the mean.
D)mortality.

Question 17

After participating in an experiment on the effects of alcohol on sociability,Megan could not wait to return to her sorority house to tell all of her sisters about it.In this situation,the researcher should be concerned with the confound of

A)mortality.
B)regression to the mean.
C)testing.
D)diffusion of treatment.

Question 18

Internal validity is

A)the extent to which the results of an experiment can be attributed to the manipulation of the dependent variable,rather than to some confounding variable.
B)the extent to which the results of an experiment can be attributed to the manipulation of the independent variable,rather than to some confounding variable.
C)the extent to which the results of an experiment can be generalized.
D)both b and c

Question 19

The best advice for those considering retaking the SAT is that if your score was below average you probably ____ retake the test,and if your score was above average you probably ____ retake the test due to _____.

A)should; should; mortality
B)should; should not; regression to the mean
C)should not; should; regression to the mean
D)should; should not; mortality

Question 20

Alison's bathroom scale will not register a weight of more than 130 pounds.Alison does not realize this,and therefore is unaware that she has put on a few pounds until she begins to notice how tight her clothes are.This illustrates the confound of a _____ effect.

A)ceiling
B)floor
C)practice
D)fatigue

Question 21

Sometimes it is difficult to generalize the results of a study to the population because of the _____ problem.

A)diffusion of treatment
B)college sophomore
C)regression to the mean
D)mortality

Question 22

What is the relationship between external validity and the college sophomore problem?

Question 23

In an experimental study of the effects of exercise on stress,subjects are randomly assigned to either the no exercise or the exercise conditions.Identify what type of study this is-between-,within-,or matched-subjects.In addition,identify the independent and dependent variables and the control and experimental groups.

Question 24

Briefly explain the confounds of testing and regression to the mean.

Question 25

Briefly explain the confounds of history and maturation.

Question 26

_____ is a strength of matched-subjects designs but a weakness of between-subjects designs.

A)Equivalency of groups
B)Minimized testing effects
C)Minimized demand characteristics
D)none of the above

Question 27

Concerns for within-subjects designs frequently include _____ and _____.

A)order effects; nonequivalent control groups
B)carryover effects; mortality
C)carryover effects; order effects
D)all of the options are correct

Question 28

Differentiate between an exact replication,a systematic replication,and a conceptual replication.

Question 29

A problem for within-subjects designs in which the order of the conditions has an effect on the dependent variable is

A)counterbalancing.
B)order effects.
C)a Latin square effect.
D)the individual differences effect.

Question 30

What are the advantages and disadvantages in the use of a posttest-only control group design versus a pretest-posttest control group design?

Question 31

A health magazine recently reported a study in which researchers claimed that iron supplements increased memory and problem-solving abilities in a random sample of college women.All of the women took memory and problem-solving tests at the beginning of the study,then took iron supplements,and then took the same tests again at the end of the study.What is wrong with this design? What confounds could be leading to the results of improved memory and problem-solving skills?

Question 32

_____ are more of a concern for _____-subject designs,but tend not to be as great a concern for _____-subject designs.

A)Order effects; within; between
B)Order effects; between; within
C)Demand characteristics; between; within
D)none of the options is correct

Question 33

Which of the following is a type of correlated-groups designs?

A)within-subjects designs
B)matched-subjects designs
C)between-subjects designs
D)both within-subjects designs and matched-subjects designs

Question 34

Briefly explain the relationship between participant effects,experimenter effects,single-blind experiments,and double-blind experiments.

Question 35

A design in which the same participants are used in each condition is a _____ design.

A)matched-subjects
B)between-subjects
C)within-subjects
D)across-subjects

Question 36

When we use different subjects in each condition,but they are related on some variable or variables,we are using a _____ design.

A)matched-subjects
B)between-subjects
C)within-subjects
D)across-subjects

Question 37

A mechanism for controlling order effects ether by including all orders or treatment presentations or by randomly determining the order for each participants is

A)ordering.
B)counterbalancing.
C)a Latin square.
D)counterbalancing and a Latin square.

Question 38

Briefly explain the confounds of instrumentation and mortality.

Question 39

A design in which the participants in the experimental and control groups are related in some way is a _____ design.

A)correlated-groups
B)between-subjects
C)across-subjects
D)none of the options is correct

Question 40

What is a confound and how is it related to internal validity?

Question 41

Identify the two types of correlated-groups designs discussed in the text and explain why each is considered a correlated-groups design.

Question 42

Explain what a Latin square is and how it helps with counterbalancing.

Question 43

Explain what counterbalancing is,how it is achieved,and which confound it helps to minimize.