Deck 12: Experiments and Quasi-Experiments

Question 1

Suppose a case management program is established to reduce rehospitalization rates in a hospital and that those rates drop dramatically once the new program is established.We can conclude that

A) research has demonstrated an effective approach to practice.
B) causality cannot be inferred because time order was not established.
C) another event occurring during the time of the study might explain away the change.
D) the absence of covariation threatens the internal validity of any causal inferences.

Answer 1

C

Question 2

The problem of an interaction between the testing and the experimental stimulus is handled by

A) the Solomon four-group design.
B) quasi-experimental designs.
C) the classical experimental design
D) all of these.

Answer 2

A

Question 3

An instrumentation effect occurs when

A) the instrument employed for the pretest has an effect that shows up on the posttest.
B) the measurement instrument is changed from the pretest to the posttest.
C) there is a change on the dependent variable from the pretest score to the posttest score.
D) all of these.

Answer 3

B

Question 4

Which of the following is LEAST suited to providing clear evidence about a causal relationship between the independent and dependent variables?

A) classical experimental design.
B) Solomon four-group design.
C) posttest-only control group design.
D) one-shot case study.

Question 5

Assume that you have developed a study technique that you believe will result in students scoring higher on research methods exams.You test your study technique with the design diagrammed below.
R = random assignment
0 = observation
X = stimulus
R 01 X 02
R 03 04
Using the diagrammed design,what predictions will you make?

A) 02 should be greater than 01.
B) 02 should be greater than 04.
C) 04 should be greater than 03.
D) 02 should be greater than 01 and 04

Question 6

Quasi-experimental designs are often used instead of experimental designs because

A) agency constraints often make experiments infeasible.
B) they have more internal validity than experiments
C) quasi-experiments randomly assign participants to groups.
D) all of these.

Question 7

For a causal relationship to exist there must be evidence

A) of a relationship between variables.
B) that one variable precedes the other in time.
C) that a third variable did not cause the changes observed in the first two variables.
D) all of these.

Question 8

When selecting a comparison group in a quasi-experimental design,one should

A) select a group unlike the experimental group.
B) select a group as similar as possible to the experimental group.
C) use random assignment.
D) none of these

Question 9

The classic experiment with random assignment of participants controls for:

A) research reactivity
B) measurement bias
C) diffusion or imitation of treatments
D) compensatory equalization and rivalry
E) resentful demoralization
F) all of these
G) none of these

Question 10

A friend of yours,a senior,took the Graduate Record Exam in September and scored in the 99th percentile.In February your friend took the same exam over again.This time your friend scored in the 84th percentile.As a research methodology student,you told your friend that his/her lowered score was probably due to

A) testing.
B) history.
C) statistical regression.
D) demoralization.
E) compensation rivalry.

Question 11

The design diagrammed in question 8

A) treats 0 as the new teaching technique.
B) treats 0 as the old teaching technique.
C) treats X as the scores on the research methods exam.
D) none of these.

Question 12

Which of the following is NOT a characteristic of a cross-sectional study?

A) It is conducted at only one point in time.
B) It can be exploratory, descriptive, or explanatory.
C) It concentrates on the changes that take place within a specific sample over a period of time.
D) It provides a means for studying a large variation in the population at the same point in time.

Question 13

The 55-mph speed limit was introduced in the U.S.in 1973.Shortly thereafter the number of auto accidents declined.We can conclude that

A) the reduced speed limit caused the decline in auto accidents.
B) the reduced speed limit may have caused the decline in the number of auto accidents.
C) the reduced speed limit and the number of auto accidents are causally related.
D) the reduced speed limit had nothing to do with the decline in auto accidents.

Question 14

Suppose a new social casework program is offered to students with high levels of truancy.If those students placed in the program by their families have significantly less truancy after participating than the students who did not participate in the program,then we can conclude that

A) the program effectively reduces truancy.
B) a selection bias might explain away the difference.
C) causality cannot be inferred because of the lack of covariation.
D) some clients benefited, so the program has value.

Question 15

Whenever two variables are correlated,we may assume that one is the cause of the other.

Question 16

Pre-experimental designs

A) are the weakest experimental designs.
B) control for most sources of internal invalidity.
C) control for most sources of external invalidity.
D) are excellent for drawing causal inferences.

Question 17

The Solomon four-group design

A) combines the classical experimental design with the posttest-only control group design.
B) combines the classical experimental design with the pretest-only control group design.
C) combines the classical experimental design with the static-group comparison design.
D) combines the static-group comparison design with the one-group pretest-posttest design.

Question 18

A school social worker administered a self-esteem test to a group of 9th graders in September.During the school year the students received intensive social work intervention designed to improve their self-esteem.In May the self-esteem test was given again and the self-esteem scores improved.A major problem in this research is that the researcher failed to control for

A) history.
B) maturation.
C) testing.
D) selection biases.
E) all of these.

Question 19

If we can establish that variable X comes before variable Q in time,then we can say

A) variable X is a cause of variable Q.
B) variable X is not a cause of variable Q.
C) variable Q is a cause of variable X.
D) variable Q is not a cause of variable X.

Question 20

Which of the following statements is true about case-control designs?

A) They rarely are feasible.
B) Data must be collected at multiple points in time.
C) Retrospective data are collected about past differences that might explain differences in outcome.
D) We usually can be highly confident about their internal and external validity.
E) We usually can be highly confident about the direction of causal influence.

Question 21

Without using appropriate experimental and control groups,extraneous events in subjects' lives can make history a threat to internal validity,even if those events are of no historical importance to people in general.

Question 22

Attrition effects are automatically controlled when participants are assigned randomly to experimental and control groups.

Question 23

The problem of external validity refers to the generalizability of results.

Question 24

What differentiates experimental from pre-experimental designs? Give an illustration of a situation in which an experimental design would be preferred and one in which a pre-experimental design would be acceptable.

Question 25

Case-control designs have more controls for threats to validity than do most other designs for evaluating programs or practice.

Question 26

Quasi-experiments using nonequivalent comparison groups without random assignment can be credible,assuming that the comparability of the experimental and comparison groups is plausible-especially if the researcher provides substantial evidence of that comparability.

Question 27

Explain what is meant by internal and external validity.

Question 28

Random assignment to experimental and control groups controls for research reactivity.

Question 29

The classic experiment with random assignment of participants controls for measurement bias.

Question 30

Studies that assign subjects to intervention groups on the basis of their extreme scores are vulnerable to regression toward the mean.

Question 31

Time series designs with many measurement points control for maturation.

Question 32

The effectiveness of randomization in experimentation is affected by the number of participants involved.

Question 33

Discuss the advantages and disadvantages of cross-sectional studies and the case control design.

Question 34

Discuss how attrition can affect the validity of an experiment and describe steps to minimize attrition.

Question 35

The one-group pretest-posttest design controls for passage of time.

Question 36

Time series designs with many measurement points control for statistical regression.

Question 37

Professor Rose was asked to design an experiment to test whether obese people would lose weight on a new diet plan.Professor Rose was not a methodologist.Rose asked for your help.You immediately told Rose that the selected design would have to be sensitive to the issues of statistical regression,diffusion or imitation of treatment,compensatory rivalry,and demoralization.Rose said,"I don't understand." Explain these issues to Rose.Suggest and explain a design that would control for these problems.

Question 38

Explain the elements of the class experimental design.Is this design especially useful in dealing with causal relationships? If yes,why? If not,why?