Question 1

One problem with the pretest-posttest design is that participants:
A)cannot be randomly assigned to groups.
B)are sensitized about the true purpose of the experiment.
C)drop out of the experiment.
D)cannot be divided into two equivalent groups.

Accepted Answer

Participants may become sensitized to the true purpose of the experiment because they are given the pretest before the treatment, which may give them clues about what the experiment is testing. This could potentially affect their behavior and the results of the study.

Question 2

Nada designs a study in which she has two control and two experimental groups. In the design, one control group and one experimental group receive a pretest each, while the other control group and experimental group do not. Nada's design is an example of a _____ design.
A)four-group pretest-posttest
B)Solomon four-group
C)two-group control
D)one-group control-one-group experimental

Accepted Answer

Nada's design is an example of a Solomon four-group design, which includes two experimental and two control groups. One of each receives a pretest, while the other one does not. This allows for testing the effect of the pretest on the outcome variable and controlling for pre-existing differences between groups.

Question 3

In a _____ design, half the participants receive only a posttest, while the other half receives both a pretest and a posttest.
A)pretest-posttest
B)one-group pretest-posttest
C)Solomon four-group
D)two-group pretest-posttest

Accepted Answer

The Solomon four-group design is a research method that involves four groups to assess the effects of a treatment or intervention. Two groups receive a pretest (one of these groups receives the treatment, and the other does not), and two groups do not receive a pretest (again, one of these receives the treatment, and the other does not). This design helps to evaluate both the impact of the treatment and the effect of having a pretest on participants' responses.

Question 4

In an experimental design, which of the following is a researcher least likely to do if the awareness of a pretest poses a problem?
A)The researcher is least likely to disguise the pretest.
B)The researcher is least likely to embed the pretest in a set of irrelevant measures.
C)The researcher is least likely to employ a Solomon four-group design.
D)The researcher is least likely to tell the participants what is being studied and why.

Accepted Answer

If the awareness of a pretest poses a problem, the researcher may opt not to inform participants of the pretest. This means that the researcher is least likely to tell the participants what is being studied and why, as indicated in option D. Disguising the pretest (option A) or embedding it in a set of irrelevant measures (option B) are strategies that could be employed to minimize the awareness of the pretest. A Solomon four-group design (option C) involves using two groups (one with a pretest and one without) and two control groups (one with a posttest only and one with neither pretest nor posttest) to test the effect of pretesting. While this design can be used to address the problem of pretest awareness, it is not the least likely option.

Question 5

Which of the following is an advantage of using a pretest-posttest design over using a posttest-only design?
A)It assesses whether the groups are equivalent.
B)It enables participants to figure out what is being studied and why.
C)It uses less time to conduct the experiment.
D)It minimizes demand characteristics.

Accepted Answer

A pretest-posttest design allows researchers to assess whether the groups are equivalent before the treatment is administered, which increases the internal validity of the study. In contrast, a posttest-only design does not provide information about group equivalence and is therefore more susceptible to selection bias. B is incorrect because both designs can lead to participants figuring out what is being studied and why. C is also incorrect because a pretest-posttest design usually takes more time than a posttest-only design due to the need to administer the pretest. D is incorrect because a pretest-posttest design may actually increase demand characteristics since participants may alter their behavior based on their performance on the pretest.

Question 6

Mortality in experimental design refers to the fact that participants:
A)cheat on questionnaires.
B)engage in intragroup conflict.
C)drop out of an experiment.
D)provide false responses.

Accepted Answer

Mortality in experimental design refers to participants dropping out of the experiment, which can ultimately reduce the sample size and affect the validity of the results. Cheating on questionnaires, intragroup conflict, and providing false responses are not directly related to mortality in experimental design.

Question 7

At the end of a three-year study, Lene finds that 12 percent of her participants did not take part in the final survey because they moved away to another city. In research terms, Lene is experiencing issues related to _____.
A)maturation
B)testing
C)regression
D)mortality

Accepted Answer

Mortality refers to the loss of participants during the course of a study, and in this case, Lene's loss of participants is due to them moving away from the area, which is a form of mortality. Maturation refers to changes in participants over time, testing refers to the effects of repeatedly taking a test, and regression refers to the tendency for extreme scores to move closer to the mean on subsequent testing.

Question 8

Colin wants to find out how using fins increases swimming speed. If an independent groups design is used, the researcher would manipulate the variable by:
A)randomly requiring half the swimmers to swim without fins and the other half to swim with fins.
B)having all swimmers first swim without fins and then with fins.
C)having half the swimmers first swim without fins and then with fins and having the other half swim first with fins and then without fins.
D)requiring all swimmers to first swim with fins and then without fins.

Accepted Answer

In an independent groups design, participants are divided into separate groups where each group experiences a different condition. Option A correctly describes this by having one group swim with fins and the other without, thus manipulating the independent variable (use of fins) across different groups.

Question 9

Sasha, a psychologist, has participants serve as their own control group by having them take part in every condition of her study. This experimental approach is an example of a(n) _____.
A)one-shot case study
B)simple random design
C)independent groups design
D)repeated measures design

Accepted Answer

Sasha's experimental approach involves participants serving as their own control group, meaning they will take part in every condition of the study. This is a characteristic of a repeated measures design. Therefore, the correct answer is (D) repeated measures design. The other options are not applicable to Sasha's experimental approach. A one-shot case study involves measuring a single group at only one point in time, a simple random design involves randomly assigning participants to different groups, and an independent groups design involves comparing two or more separate groups.

Question 10

In a _____ design, comparisons are made among the same group of participants.
A)matched sets
B)natural sets
C)within-subjects
D)random assignment

Accepted Answer

A within-subjects design, also known as a repeated-measures design, tests participants on the same measures at multiple time points or under different conditions. This design allows for a direct comparison of the individual's scores, eliminating the need for matching or random assignment of participants to different groups.

Question 11

In a Solomon four-group design, if there is no impact of the pretest, _____.
A)the posttest scores will be different for all the groups
B)the pretest scores will be different for all the groups
C)the posttest scores will be the same for all the groups
D)the posttest scores will not be affected

Accepted Answer

In a Solomon four-group design, if there is no impact of the pretest, the posttest scores will be the same for all the groups. This is because the pretest does not affect the outcome, and so the groups that receive the pretest will not have an advantage or disadvantage in the posttest scores. Therefore, the posttest scores will be equivalent across all four groups.

Question 12

Jeanne wants to know whether wearing sunglasses improves driving performance. If an independent groups design is used, the researcher would manipulate the variable by:
A)randomly requiring half the drivers to drive with sunglasses, and the other half to drive without sunglasses.
B)having all drivers first drive without sunglasses and then with sunglasses.
C)having half the drivers first drive without sunglasses and then with sunglasses and having the other half first drive with sunglasses and then without sunglasses.
D)requiring all drivers to first drive with sunglasses and then without sunglasses.

Accepted Answer

An independent groups design involves randomly assigning participants to either the experimental or control group. In this case, the variable being manipulated is whether or not the driver is wearing sunglasses. Therefore, the best option is to randomly require half of the drivers to wear sunglasses while driving and the other half to drive without sunglasses. This way, any potential differences in driving performance can be attributed to the variable being manipulated (wearing sunglasses) and not to other factors. Choice B, C, and D do not involve random assignment and are therefore not appropriate for an independent groups design.

Question 13

In order to observe the influence of environmental factors on alcohol consumption, Leila asks participants to come to her laboratory, fill out a questionnaire, and consume alcohol. She finds that over time, fewer and fewer participants show up to take part in the experiment. This decrease in the number of participants in the experiment is called _____.
A)the carryover effect
B)mortality
C)regression
D)the order effect

Accepted Answer

The decrease in the number of participants in the experiment over time is called "mortality." This refers to participants dropping out or being lost from the study, which can impact the validity and generalizability of the results. The other options (carryover effect, regression, and order effect) do not accurately describe this phenomenon.

Question 14

Which of the following accurately describes a disadvantage of using a pretest-posttest design?
A)It maximizes participant mortality.
B)It promotes attrition.
C)It is time-consuming.
D)It does not allow one to rule out regression effects.

Accepted Answer

Pretest-posttest designs are time-consuming because they require measurements to be taken at least twice for each participant: once before the intervention or treatment (pretest) and once after (posttest). This can significantly increase the duration of the study compared to designs that do not require multiple measurements.

Question 15

Gerard conducts a study to examine the effectiveness of an exercise program on obese people. The participants must exercise for one hour every day for six months. By the end of the fourth month, Gerard finds that 75 percent of the participants dropped out of the study. What kind of problem has Gerard encountered in his study?
A)Maturation
B)Morbidity
C)Attrition
D)Selection

Accepted Answer

Gerard has encountered attrition, which is the loss of participants during a study. In this case, 75 percent of the participants dropped out before the study was complete. Maturation refers to changes that occur naturally over time and could affect the results. Morbidity refers to the prevalence of disease or illness in a population. Selection refers to potential bias when choosing participants for a study.

Question 16

Elena randomly asks students of a class to taste either Coke or Pepsi. Students rate their liking for the soda they taste on a scale of 1 to 10. This is an example of a _____ design.
A)pretest-posttest
B)posttest-only
C)pretest only
D)one-group posttest

Accepted Answer

This is an example of a posttest-only design because the students are only asked to rate their liking for the soda once, after they have tasted it. There is no pretest to establish a baseline or to compare the ratings to later.

Question 17

When individuals participate in only one condition, it is a(n) _____ design. When individuals participate in all conditions, it is a _____ design.
A)single group; full measure
B)partial; whole
C)group; multi-group
D)independent groups; repeated measures

Accepted Answer

When individuals participate in only one condition, it is an independent groups design. When individuals participate in all conditions, it is a repeated measures design. Therefore, the best choice is D, which correctly identifies the two types of designs.

Question 18

Ahmed conducts a study to test the effectiveness of a drug. He surveys the clients twice-once at intake and then six months later. He finds that the drug was overall effective, but approximately 55 percent of the original sample stopped using the drug. Therefore, he does not have posttest data for them. In this case, what is likely to be an alternative explanation for the results obtained by Ahmed?
A)Maturation
B)Mortality
C)Statistical regression
D)Diffusion of treatment

Accepted Answer

Mortality refers to the loss of participants during a study, and it can be a threat to the validity of the results. In this case, since 55% of the original sample stopped using the drug, there is a possibility that those who continued using the drug might be a biased subset of the original sample. This can lead to an overestimation of the effectiveness of the drug, and the results may not generalize to the larger population. Therefore, mortality is a potential alternative explanation for the results obtained by Ahmed.

Question 19

A design that assigns different participants to each condition using random assignment is a(n) _____ design.
A)independent groups
B)repeated measures
C)Solomon four-group
D)pretest-posttest

Accepted Answer

In an independent groups design, different participants are randomly assigned to each condition, which helps to eliminate potential confounding variables and increase the internal validity of the study. Choice B, repeated measures, involves each participant being tested in all conditions, which can be problematic if there is a carryover effect or if the testing itself influences subsequent performance. Choice C, Solomon four-group, involves combining elements of both independent groups and pretest-posttest designs, which may not always be necessary or practical. Choice D, pretest-posttest, involves testing participants before and after some intervention, but does not ensure equal allocation of participants to each condition. Therefore, an independent groups design is the best choice for assigning different participants to each condition using random assignment.

Question 20

Aisha wants to examine the effect of room temperature on task performance. She places one group of participants in a room that is set to a temperature of 54 degrees, a second group in a room that is set to a temperature of 72 degrees, and a third group in a room that is set to a temperature of 90 degrees. She then measures the amount of time it takes each group to complete the same task. This design would best represent a(n) _____ design.
A)independent groups
B)repeated measures
C)three-group pretest-posttest
D)pretest-posttest

Accepted Answer

This design is an independent groups design because each group experiences a different level of the independent variable (room temperature) and there is no overlap between the participants in each group.

Quiz 8: Experimental Design

One problem with the pretest-posttest design is that participants:

Nada designs a study in which she has two control and two experimental groups. In the design, one control group and one experimental group receive a pretest each, while the other control group and experimental group do not. Nada's design is an example of a _____ design.

In a _____ design, half the participants receive only a posttest, while the other half receives both a pretest and a posttest.

In an experimental design, which of the following is a researcher least likely to do if the awareness of a pretest poses a problem?

Which of the following is an advantage of using a pretest-posttest design over using a posttest-only design?

Mortality in experimental design refers to the fact that participants:

At the end of a three-year study, Lene finds that 12 percent of her participants did not take part in the final survey because they moved away to another city. In research terms, Lene is experiencing issues related to _____.

Colin wants to find out how using fins increases swimming speed. If an independent groups design is used, the researcher would manipulate the variable by:

Sasha, a psychologist, has participants serve as their own control group by having them take part in every condition of her study. This experimental approach is an example of a(n) _____.

In a _____ design, comparisons are made among the same group of participants.

In a Solomon four-group design, if there is no impact of the pretest, _____.

Jeanne wants to know whether wearing sunglasses improves driving performance. If an independent groups design is used, the researcher would manipulate the variable by:

Which of the following accurately describes a disadvantage of using a pretest-posttest design?

Elena randomly asks students of a class to taste either Coke or Pepsi. Students rate their liking for the soda they taste on a scale of 1 to 10. This is an example of a _____ design.

When individuals participate in only one condition, it is a(n) _ design. When individuals participate in all conditions, it is a _ design.

A design that assigns different participants to each condition using random assignment is a(n) _____ design.