Question 1

Which of the following is not an example of endogenous change, in which internal validity is compromised because of natural developments in the subjects, independent of experimental treatment?

Accepted Answer

The History Effect refers to external events that occur during the course of a study which can affect the participants' behavior, not internal developments within the subjects themselves.

Question 2

To establish time order, which of the following must come first?

Accepted Answer

To establish time order in an experiment or study, the independent variable must come first. This is because the independent variable is the one that is manipulated or changed to observe its effect on the dependent variable, thereby establishing a cause-and-effect relationship.

Question 3

Rachel finds that higher salaries produce greater productivity in work environments with a great deal of creative flexibility, but have no effect in routine, unskilled work. What element of causality has she identified?

Accepted Answer

Rachel has identified "Context" as the element of causality, indicating that the effect of higher salaries on productivity varies depending on the work environment, specifically whether it is creatively flexible or routine and unskilled.

Question 4

Which of the following are requirements for identifying a causal effect?

Accepted Answer

To identify a causal effect, three requirements must be met: (1) association between the two variables, (2) time order (the cause must come before the effect), and (3) nonspuriousness (meaning that the association is not due to a third variable). Option A includes all three of these requirements. Option B includes two of the requirements, but does not mention association. Option C includes nonspuriousness and mechanism but adds context instead of time order. Option D includes association and mechanism but adds context instead of time order. Option E includes association and time order but adds context instead of nonspuriousness.

Question 5

A researcher is concerned that gender may affect how subjects respond to an experimental stimulus. So subjects are paired with another subject who has the same gender, and one member from each pair is assigned by a flip of a coin to the experimental group and one to the control group. This method of assigning subjects to groups is called:

Accepted Answer

Matching is the method of pairing subjects based on a specific characteristic, in this case, gender. The flip of a coin is used for random assignment after the pairs are made. Quotas, stratified randomization, and nonprobability sampling are not applicable in this scenario. Random assignment is used after pairs are made, but the key method of pairing is matching.

Question 6

The reason that ex post facto control group designs are not considered quasi-experimental is:

Accepted Answer

Ex post facto control group designs, also known as retrospective control group designs, select the control group after the treatment has already occurred. This means that there is no random assignment to the control group, and therefore is not considered a true experimental design. The lack of random assignment for control groups is the key reason why ex post facto control group designs are not considered quasi-experimental.

Question 7

A university conducts a series of surveys in which subjects are drawn from first year and graduating students and finds that graduating students demonstrate much higher rates of approval for the university (in terms of whether they think the classes were relevant, the instructors were competent, etc.). The university then claims that more experience with the university leads to higher approval. What source of internal invalidity has the university not considered?

Accepted Answer

The answer of A university conducts a series of surveys...

Question 8

Two types of before-and-after experimental designs in which multiple pretest and posttest observations are made of the same group are:

Accepted Answer

Repeated measure panel designs and time series designs both involve multiple pretest and posttest observations of the same group, allowing for analysis of changes over time.

Question 9

The process through which the independent variable creates changes in a dependent variable is known as a(n):

Accepted Answer

The process of how the independent variable affects the dependent variable is known as a mechanism. The other options are not relevant to this definition.

Question 10

To say that variables have an association is to say that:

Accepted Answer

When we say that variables have an association, we mean that they vary together empirically. This does not necessarily imply causation or a genuine relationship between the variables, and it does not require them to occur at the same point in time. So, option C is the best answer.

Question 11

Quasi-experimental designs are like true experiments, except:

Accepted Answer

Quasi-experimental designs do not randomly assign subjects to groups, unlike true experiments. This lack of random assignment makes it difficult to establish a cause-and-effect relationship between the independent variable and dependent variable.

Question 12

In an experiment, measurement of the dependent variable after the experimental treatment is known as:

Accepted Answer

The dependent variable is the variable that is being measured to see if it is affected by the independent variable (the experimental treatment). Posttest refers to the measurement of the dependent variable after the experimental treatment has been applied. Pretest would refer to measurement of the dependent variable before the experimental treatment. Control-test and matching are not relevant to this definition.

Question 13

A true experiment allows the establishment of nonspuriousness through:

Accepted Answer

Random assignment into two or more comparison groups is the only method that can establish nonspuriousness and eliminate the possibility of a third variable causing the observed relationship between the independent and dependent variables. The other options may help to control for certain variables, but they do not provide the same level of control as random assignment.

Question 14

After 30 years of teaching the same research methods course, Professor Zone's average exam scores increase because he doesn't want to spend the time arguing with students over borderline grades. This is an example of:

Accepted Answer

This situation fits the definition of instrumental decay, which occurs when the effect of the treatment weakens over time and the instrument becomes less effective. In this case, Professor Zone's approach of giving borderline students higher grades is a form of treatment, and over time he has weakened the effectiveness of the grading system, leading to higher average scores.

Question 15

When a staff member explains to a subject why he or she has been deceived in an experiment, what is the staff doing?

Accepted Answer

The staff member is engaging in debriefing, which involves explaining to the subject the true purpose and nature of the experiment after deception has occurred.

Question 16

When parents are registering their children for kindergarten, they are given the opportunity to enroll their children in an experimental music program that researchers hope will improve overall learning. What experimental design is being used?

Accepted Answer

This is a non-equivalent control group design, with the experimental group being the children enrolled in the music program and the control group being those who are not. By comparing the academic performance of the two groups, the researchers hope to determine the impact of the music program on learning.

Question 17

After they had failed the writing exam that was required of all students before graduation, fifteen students were placed in a class in which they received additional tutoring. After completing this class, all fifteen students retook the exam earned higher scores. Their success was held up as an example that the class curriculum really works. What source of internal invalidity has not been considered?

Accepted Answer

The source of internal invalidity that has not been considered is regression. This is because students who initially score very low (as these fifteen did) will naturally tend to have higher scores on the second test, regardless of whether or not they received additional tutoring. This is a statistical phenomenon known as regression to the mean. Therefore, it cannot be concluded that the improved scores were solely due to the effectiveness of the class curriculum.

Question 18

A spurious relationship between two variables is:

Accepted Answer

A spurious relationship between two variables is a false relationship that appears to exist between two variables but is actually caused by a third variable. Therefore, it is not a valid or reliable relationship and it is not causal. It may also not be compensatory as this refers to a relationship where an increase in one variable is compensated by a decrease in the other variable, which does not necessarily imply a spurious relationship.

Question 19

The common feature of all before-and-after designs is:

Accepted Answer

Before-and-after designs involve all cases receiving the experimental treatment, with measurements taken both before and after the intervention to assess its effects.

Question 20

A procedure that assesses that treatment and measurement are consistent throughout an experiment is a(n):

Accepted Answer

A process analysis examines the consistency and accuracy of procedures used in an experiment, including the treatment and measurements. This helps ensure that the results are reliable and valid. The other options are not directly related to assessing consistency and accuracy in an experiment.

Quiz 6: Causation and Experimental Design