Question 1

A randomized field experiment is designed to test the usefulness of a new DNA test for solving crimes. Crime clearance rates in police departments that use the new DNA test will be compared with crime clearance rates in police departments that use traditional DNA tests. The fact that some departments will not be using this new DNA test to solve crimes during the experiment may be ethically justifiable when ______.

Accepted Answer

The ethical justification for not using the new DNA test in some departments hinges on the uncertainty of its value in solving crimes. If the effectiveness of the new test is unknown, withholding it for the purpose of a controlled experiment can be ethically justified to assess its utility.

Question 2

A researcher is testing the effectiveness of a new boat paddle by holding a race between two teams. When the control team realizes that it received traditional paddles instead of the new paddles that the experimental team received, the control team members feel as though they have no chance of winning and put forth little effect in the race. This is an example of ______.

Accepted Answer

This scenario describes demoralization, where the control team feels discouraged upon realizing they have traditional paddles, leading to reduced effort in the race.

Question 3

All of the following are accurate statements about pretests and posttests EXCEPT ______.

Accepted Answer

A pretest is not a mandatory component for a study to be classified as an experiment. An experiment primarily requires manipulation of independent variables and observation of their effects on dependent variables. Pretests are useful for establishing baselines but are not strictly necessary for all experimental designs.

Question 4

Which design has no comparison group?

Accepted Answer

Before-and-after designs lack a comparison group because they measure outcomes in the same group of subjects before and after an intervention, without comparing to a separate control group.

Question 5

A time series (repeated measures) design is a type of ______.

Accepted Answer

A time series design involves collecting data over time before and after a treatment or intervention to observe changes, fitting the description of a "before-and-after" study design.

Question 6

Which of the following is NOT a source of internal invalidity?

Accepted Answer

Statistical control is a method used to account for potential confounding variables, not a source of internal invalidity.

Question 7

All of the following are types of endogenous change EXCEPT ______.

Accepted Answer

Endogenous changes refer to changes that originate from within the system or organism being studied. Testing, maturation, and regression are all examples of endogenous changes because they naturally occur as part of the internal processes or development of the system or organism. Selection bias, however, is not an endogenous change; it is a type of error that occurs when the sample chosen for a study is not representative of the population being studied, which is an external factor affecting the study's outcomes.

Question 8

In the process of conducting an experiment, a researcher administers a survey before the treatment is applied, in order to provide a baseline against which to judge the results. This survey is a ______.

Accepted Answer

A pretest is administered before the treatment in an experiment to establish a baseline for comparing the effects of the treatment.

Question 9

Which of the following is NOT required for a true experiment?

Accepted Answer

A pretest is not strictly required for a study to be considered a true experiment. True experiments primarily require random assignment and a control group to establish causality. A pretest is useful for measuring change, but its absence does not disqualify a study from being a true experiment.

Question 10

A researcher conducts a study on the effectiveness of a new prisoner rehabilitation program. All of the elements of an experiment are present except that the groups were not randomly assigned. This study is an example of a(n) ______.

Accepted Answer

The absence of random assignment in a study that otherwise has all the elements of an experiment, including a control group, makes it a nonequivalent control group design. This design involves comparing groups that are not created through random assignment, which can introduce selection bias but is often used in situations where random assignment is not feasible.

Question 11

All of the following are accurate statements about factorial surveys EXCEPT which of the following?

Accepted Answer

Factorial surveys can include control groups or conditions as part of their design, making them not inherently quasi-experimental due to a lack of control group. They are designed to systematically manipulate and test the effects of various factors within vignettes, allowing for experimental control and comparison.

Question 12

In a study of the effectiveness of a new cancer drug, the researcher administering the medication is unaware of which patients are receiving the new drug and which are receiving a placebo. This is an example of ______.

Accepted Answer

This is an example of a double-blind procedure, where neither the participants nor the researchers know who is receiving the actual treatment versus a placebo, reducing bias in the study's results.

Question 13

Which of the following is an accurate statement about the Solomon four-group design?

Accepted Answer

The Solomon four-group design is a method used to control for the effects of pretesting. In this design, only some of the groups receive the pretest, allowing researchers to assess the impact of the pretest on the results.

Question 14

A worthwhile, conservative strategy for minimizing the possibility of invalid causal conclusions due to differential attrition is ______.

Accepted Answer

Basing the outcome analysis on comparing all subjects initially assigned to each condition (intention-to-treat analysis) helps minimize bias due to differential attrition by including all participants regardless of whether they completed the study.

Question 15

______ is a defining feature of a true experiment.

Accepted Answer

Random assignment is a defining feature of a true experiment because it ensures that each participant has an equal chance of being assigned to any group, thereby reducing selection bias and increasing the internal validity of the experiment.

Question 16

The ______ can be considered as the variable that is manipulated in an experiment.

Accepted Answer

The treatment variable, also known as the independent variable, is the one that is manipulated or changed by the researcher in an experiment to observe its effect on the dependent variable.

Question 17

Multiple ______ can be adminstered to examine how long a treatment effect may be observed.

Accepted Answer

Posttests are administered after a treatment to measure its effects and can be repeated to observe how long the treatment effect lasts.

Question 18

Random assignment removes ______ from the assignment process.

Accepted Answer

Random assignment is a method used in experiments to distribute participants across different groups in a way that each participant has an equal chance of being assigned to any group. This process is designed to eliminate bias in the assignment process, ensuring that the groups are comparable at the start of the experiment.

Question 19

An example of a variable that is often used in matching procedures would include which of the following?

Accepted Answer

Age, gender, and year in school are all common variables used in matching procedures to ensure that the groups being compared are similar on these key characteristics. This helps in controlling for these variables' potential confounding effects on the outcome of interest.

Question 20

In the Sherman and Berk (1984) domestic violence experiment, which of the following was considered the treatment condition?

Accepted Answer

In the Sherman and Berk (1984) domestic violence experiment, the treatment condition was arrest. The study aimed to evaluate the effectiveness of arrest in deterring future domestic violence incidents compared to other interventions like separation or no intervention.

Quiz 7: Experimental Designs