Question 1

Which of the following is valuable but non-essential feature of a true experiment?

Accepted Answer

Complete control over the experiment's context is valuable for reducing confounding variables and increasing the validity of the experiment's findings. However, it is not always essential or feasible, especially in field experiments or when studying complex phenomena in natural settings. Random assignment, assessment of change in the dependent variable, and having both an experimental group and a control group are considered essential features for the validity of a true experiment.

Question 2

Which of the following is a requirement for the pretest in an experiment?

Accepted Answer

D

Question 3

Randomization in experimental research ______.

Accepted Answer

Randomization helps ensure that any differences between groups are due to chance rather than systematic bias, thus enhancing the internal validity of the experiment.

Question 4

How do randomization and random sampling differ?

Accepted Answer

Random sampling is used to select a representative sample from a population to increase the generalizability of the results. Randomization, often used in experimental designs, involves randomly assigning participants to different groups (e.g., treatment vs. control) to ensure that any differences between and within the groups are not systematic at the outset of the experiment, thereby reducing the likelihood that observed differences in outcomes are due to variables other than the one being studied.

Question 5

When matching is used to assign subjects to an experimental and a comparison group, the resulting research design is:

Accepted Answer

Matching attempts to pair subjects in experimental and comparison groups based on certain characteristics to ensure the groups are equivalent on those characteristics. However, this process can inadvertently introduce or fail to control for other differences between the groups, potentially weakening the research design.

Question 6

A researcher is interested in examining the effect that participation in D.A.R.E. has on future drug use. In her experiment, she identifies one student who has completed the D.A.R.E. program and matches the student to another who is similar in most respects except he or she has not completed D.A.R.E. This is an example of ______.

Accepted Answer

This is an example of individual matching because the researcher is pairing one participant who has completed the D.A.R.E. program with another participant who has not, based on their similarities in most respects other than their participation in D.A.R.E.

Question 7

The key feature of an experimental design that distinguishes it from a quasi-experimental design is the ______.

Accepted Answer

The key feature that distinguishes an experimental design from a quasi-experimental design is the random assignment of participants to two or more groups. This allows for the control of confounding variables and ensures that differences between groups can be attributed to the manipulation of the independent variable, rather than to pre-existing differences between the groups.

Question 8

A researcher wants to study the effectiveness of a midnight basketball program in reducing juvenile delinquency. She identifies a community that already has a program in place and compares delinquency rates to a community that does not. This is an example of which type of quasi-experimental design?

Accepted Answer

This is an example of a non-equivalent control group design because the researcher is comparing outcomes (delinquency rates) between two groups (one with the midnight basketball program and one without) that were not randomly assigned.

Question 9

Before-and-after designs are distinguished from other quasi-experimental designs by which of the following?

Accepted Answer

Before-and-after designs typically lack a traditional comparison group, focusing instead on comparing conditions or outcomes for the same subjects before and after an intervention.

Question 10

Which of the following is the reason that ex post facto control group design should be considered nonexperimental rather than quasi-experimental?

Accepted Answer

In ex post facto designs, the comparison group is identified after the intervention, which means there is no manipulation or control over the assignment to groups, making it nonexperimental.

Question 11

A quasi-experimental design is just as strong on which of the following criterion as an experimental design?

Accepted Answer

A quasi-experimental design can establish an association between the independent and dependent variables, similar to an experimental design. However, it may not control for all confounding variables as effectively as a true experimental design, which affects the ability to establish causation.

Question 12

A researcher is seeking to maximize generalizability of results. Which research design should she use?

Accepted Answer

Field experiments are conducted in natural settings rather than in a laboratory, which helps in maximizing the generalizability of the results to real-world situations.

Question 13

In a study examining the effectiveness of an education program, subjects are given a pretest. Their scores on the posttest increased because they learned information in the pretest and not as a result of the education program. This is an issue of:

Accepted Answer

This scenario describes a situation where the improvement in posttest scores is attributed to the subjects having taken the pretest, which familiarized them with the material or the types of questions asked, rather than the educational program itself. This is a classic example of a testing effect, where the act of testing influences the outcome.

Question 14

In a study examining the effectiveness of an SAT prep course, the researcher is considering how at prettests some students might have been having a bad day and their scores were artificially low. This is an issue of ______.

Accepted Answer

This is an issue of regression, specifically regression to the mean, where extreme scores on a pretest tend to move (regress) towards the average on a posttest, which can be mistaken for a real change.

Question 15

A researcher is conducting a study examining residents' attitudes toward police. During data collection, news emerges that many police officers were involved in corruption. This is an issue of ______.

Accepted Answer

This is an issue of an external event because the news about police corruption is an unexpected occurrence outside of the study that could influence the participants' attitudes, thus affecting the study's outcomes.

Question 16

Multiple pretest and posttest measures are valuable in before-and-after designs because they decrease the possibility of internal invalidity due to ______.

Accepted Answer

Multiple pretest and posttest measures help in identifying and controlling for the effects of external events that might influence the outcome, thereby reducing the risk of attributing changes to the intervention when they might actually be due to other factors.

Question 17

In medical research, the placebo effect occurs when subjects ______.

Accepted Answer

The placebo effect is a psychological phenomenon where patients report improvements in their condition simply because they believe they are receiving treatment, even if the treatment is inactive or a "dummy" drug.

Question 18

Since social programs are delivered by human beings, ______ can be very difficult to control.

Accepted Answer

Expectancy effects, also known as observer-expectancy effects, can be difficult to control in social programs because the expectations and biases of those delivering the programs can influence the outcomes.

Question 19

A Hawthorne effect occurs when ______.

Accepted Answer

The Hawthorne effect occurs when individuals modify an aspect of their behavior in response to their awareness of being observed, as described in option C, where members of the treatment group change because their participation in the study makes them feel special.

Question 20

The features of experimental designs that make them so useful for establishing causation ______.

Accepted Answer

Experimental designs often involve controlled environments and random assignment, which can limit the generalizability of findings to broader populations, as the sample may not represent the larger population.

Quiz 7: Experimental Designs