Question 1

An industrial-organizational psychologist is hired to help increase productivity at a company. He teaches one group of workers strategies to improve productivity and has a control group who does not learn the new strategies. However, workers in the experimental group talk to their friends in the control group about the new strategies, and pretty soon everyone is using them. Which kind of problem has the psychologist encountered?
A) Mortality
B) Maturation
C) Diffusion of treatment
D) Statistical regression

Accepted Answer

The psychologist has encountered a "diffusion of treatment" problem, where the intervention intended only for the experimental group spreads to the control group, contaminating the results.

Question 2

When a pretest sensitizes participants to the treatment yet to come, researchers have a problem of
A) interaction of testing and treatment.
B) temporal generalization.
C) multiple-treatment interference.
D) convenience sampling.

Accepted Answer

When a pretest affects how participants respond to the treatment, it creates an interaction between the testing and the treatment, potentially influencing the study's outcomes.

Question 3

How should a researcher guard against diffusion of treatment?
A) Be sure to randomly assign participants to groups.
B) Do not choose participants who have very high or very low scores.
C) Check experimental equipment every day.
D) Tell participants not to talk to others about the experiment.

Accepted Answer

Telling participants not to talk to others about the experiment helps prevent them from sharing information that could influence the behavior of other participants, thus guarding against diffusion of treatment.

Question 4

Which of the following is NOT a threat to external validity?
A) Statistical regression
B) Reactive arrangements
C) Convenience sampling
D) Multiple-treatment interference

Accepted Answer

Statistical regression is a threat to internal validity, not external validity. External validity threats include factors like reactive arrangements, convenience sampling, and multiple-treatment interference, which affect the generalizability of the study results.

Question 5

Angela conducts a study demonstrating that active learning strategies in a research methods course produce greater understanding of the material than passive learning strategies. She hopes that her results will apply to other research methods courses outside of the one she studied. Angela is concerned with
A) demand characteristics.
B) temporal generalization.
C) environmental generalization.
D) statistical regression.

Accepted Answer

Angela is concerned with environmental generalization, which refers to the extent to which the results of a study can be applied to other settings or environments beyond the one in which the study was conducted.

Question 6

If participants in one treatment group become familiar with the treatment of another group and copy that treatment, the experiment has low internal validity due to
A) selection.
B) maturation.
C) statistical regression.
D) diffusion of treatment.

Accepted Answer

Diffusion of treatment occurs when participants in different groups communicate and share information about their treatments, leading to contamination and reducing the internal validity of the experiment.

Question 7

Generalizability is most closely associated with
A) internal validity.
B) external validity.
C) statistical regression.
D) instrumentation.

Accepted Answer

Generalizability refers to the extent to which research findings can be applied to settings, people, times, and measures other than the ones used in the study. This concept is most closely associated with external validity.

Question 8

What is the most important property of any experiment?
A) Environmental generalization
B) Temporal generalization
C) Population generalization
D) Internal validity

Accepted Answer

Internal validity is the most important property of an experiment as it determines whether the results can be attributed to the variables being tested rather than other factors.

Question 9

_____________ generalization refers to applying the results from an experiment to participants outside of those used in the original experiment.
A) Temporal
B) Environmental
C) Population
D) Selection

Accepted Answer

Population generalization refers to applying the results from an experiment to a broader group of individuals beyond those who participated in the original study.

Question 10

Research on racial attitudes from the 1950s may not generalize to present-day attitudes. This research exhibits low
A) population generalization.
B) temporal generalization.
C) environmental generalization.
D) internal validity.

Accepted Answer

Temporal generalization refers to the extent to which research findings can be applied to different time periods. Since racial attitudes have likely changed since the 1950s, the research may not generalize well to the present day.

Question 11

Pablo gives a racism scale to participants, then gives a half-hour lecture on racism, and then gives participants the racism scale again. Which threat to external validity should Pablo be most concerned about?
A) Multiple-treatment interference
B) Interaction of testing and treatment
C) Interaction of selection and treatment
D) Statistical regression

Accepted Answer

The interaction of testing and treatment is a threat to external validity because the pre-test may sensitize participants to the treatment, affecting their responses on the post-test.

Question 12

____________ generalization refers to applying the results from an experiment to situations that differ from those of the original experiment.
A) Population
B) Treatment
C) Temporal
D) Environmental

Accepted Answer

Environmental generalization involves applying experimental results to different settings or conditions than those in the original experiment.

Question 13

Sharon hopes that the results of her study generalize beyond the participants in her study. Sharon is concerned about ___________ generalization.
A) environmental
B) population
C) temporal
D) testing

Accepted Answer

Population generalization refers to the extent to which the results of a study can be generalized to a larger population from which the participants were drawn.

Question 14

If an experiment has diffusion of treatment, what is the likely result of such an experiment?
A) The differences between the groups would be large.
B) There would be no differences between the groups.
C) The results would not be affected by diffusion of treatment.
D) None of the above.

Accepted Answer

Diffusion of treatment occurs when the treatment given to one group affects another group, leading to reduced differences between the groups.

Question 15

Exhibiting a high degree of control over the experiment _________ internal validity and __________ external validity.
A) decreases; decreases
B) increases; increases
C) increases; decreases
D) decreases; increases

Accepted Answer

High control in an experiment increases internal validity by reducing confounding variables, but it can decrease external validity as the conditions may not reflect real-world scenarios.

Question 16

_____________ generalization refers to applying the results from an experiment to a different time period.
A) Population
B) Environmental
C) Temporal
D) Statistical

Accepted Answer

Temporal generalization involves applying the findings of an experiment to different time periods.

Question 17

Which of the following is NOT a type of generalization described in the textbook?
A) Population generalization
B) Internal generalization
C) Environmental generalization
D) Temporal generalization

Accepted Answer

Internal generalization is not a recognized type of generalization in research methodology. The other options are standard types of generalization.

Question 18

Tracy hopes that the results of her experiment are applicable to college students in general, not just the 100 students in her study. Tracy is concerned about
A) internal validity
B) statistical regression.
C) external validity.
D) demand characteristics.

Accepted Answer

External validity refers to the extent to which the results of a study can be generalized to other situations and to other people, which is Tracy's concern.

Question 19

When diffusion of treatment occurs, the researcher effectively no longer has a(n) ________ variable.
A) extraneous
B) dependent
C) independent
D) internal

Accepted Answer

Diffusion of treatment occurs when the treatment or intervention spreads to the control group, making it difficult to distinguish between the effects of the independent variable and other factors.

Question 20

A researcher should evaluate _________ validity prior to __________ validity.
A) external; internal
B) internal; external
C) interior; exterior
D) exterior; interior

Accepted Answer

Internal validity should be evaluated first to ensure that the study's design and conduct allow for a valid causal relationship before considering how generalizable the results are (external validity).

Quiz 8: Internal and External Validity

When a pretest sensitizes participants to the treatment yet to come, researchers have a problem of

How should a researcher guard against diffusion of treatment?

Which of the following is NOT a threat to external validity?

If participants in one treatment group become familiar with the treatment of another group and copy that treatment, the experiment has low internal validity due to

Generalizability is most closely associated with

What is the most important property of any experiment?

_____________ generalization refers to applying the results from an experiment to participants outside of those used in the original experiment.

Research on racial attitudes from the 1950s may not generalize to present-day attitudes. This research exhibits low

Pablo gives a racism scale to participants, then gives a half-hour lecture on racism, and then gives participants the racism scale again. Which threat to external validity should Pablo be most concerned about?

____________ generalization refers to applying the results from an experiment to situations that differ from those of the original experiment.

Sharon hopes that the results of her study generalize beyond the participants in her study. Sharon is concerned about ___________ generalization.

If an experiment has diffusion of treatment, what is the likely result of such an experiment?

Exhibiting a high degree of control over the experiment _ internal validity and __ external validity.

_____________ generalization refers to applying the results from an experiment to a different time period.

Which of the following is NOT a type of generalization described in the textbook?

Tracy hopes that the results of her experiment are applicable to college students in general, not just the 100 students in her study. Tracy is concerned about

When diffusion of treatment occurs, the researcher effectively no longer has a(n) ________ variable.

A researcher should evaluate _ validity prior to __ validity.