Question 1

For which of the following studies does the researcher not control which individuals are assigned to which group?

Accepted Answer

In a nonequivalent group design, the researcher does not have control over which individuals are assigned to which group. This is because the groups are already formed naturally, rather than being randomly assigned by the researcher. In contrast, in a between-subjects experiment, the researcher does control group assignment by randomly assigning participants to either the experimental or control group. In a within-subjects experiment, the same individuals participate in all conditions, so there is no need for group assignment. In a pre-post design, individuals serve as their own control, so there is also no group assignment.

Question 2

A researcher introduces a new mathematics program in one school district and uses a neighboring district as a no-treatment control group.After the program is in place for 6 months,the researcher intends to give the students in both districts a standardized mathematics test and then compare their scores.This research cannot be classified as a true experiment because

Accepted Answer

The research cannot be classified as a true experiment because the researcher does not control the assignment of participants to groups and therefore has a nonequivalent groups design. This means that the two groups may not be similar in terms of mathematics ability, motivation, or other relevant variables. Therefore, any differences in the posttest scores cannot be attributed solely to the program and may be due to other factors. A true experiment would involve randomly assigning participants to treatment and control groups to ensure that they are equivalent at the outset. Option A is incorrect because there may be ethical or practical reasons why the treatment can only be administered to one group. Option B is incorrect because a pretest is not always necessary in a true experiment, although it can be used to assess equivalence between groups. Option D is incorrect because a laboratory setting is not necessary for a study to be a true experiment.

Question 3

Differential research is classified as

Accepted Answer

D

Question 4

Which of the following accurately describes what is evaluated by differential research?

Accepted Answer

Differential research evaluates differences in scores between preexisting groups of participants, focusing on naturally occurring differences rather than manipulated variables.

Question 5

The basic threat to internal validity for a nonequivalent groups design is

Accepted Answer

Nonequivalent groups designs are susceptible to assignment bias because the groups are not randomly assigned, which means there may be systematic differences between the groups before the intervention or treatment. This makes it difficult to attribute any differences found between the groups to the intervention or treatment itself. Other threats to internal validity, such as history or regression, can also impact nonequivalent groups designs, but assignment bias is the most basic and fundamental threat to this type of design. Reactivity is not a major threat to internal validity in this type of design.

Question 6

A quasi-experimental design

Accepted Answer

A quasi-experimental design makes some attempts to minimize threats to validity, such as using a control group, matching participants, or selecting similar groups to compare. However, it does not have complete control over extraneous variables, and it may not manipulate the independent variable in the same way as an experiment.

Question 7

A differential research design is an example of a

Accepted Answer

The answer of A differential research design is an example...

Question 8

Which of the following accurately describes nonequivalent group design?

Accepted Answer

Nonequivalent group design involves two groups that are not equivalent at the start of the study, and the researcher cannot randomly assign participants to groups. This means that the researcher cannot control which people go into each group and cannot ensure that the groups are equivalent. Therefore, choice A accurately describes this type of design. Choices B, C, and D do not accurately describe nonequivalent group design.

Question 9

Which research design is used by a researcher comparing self-esteem scores for children from divorced families versus scores for children from families with no divorce?

Accepted Answer

The differential research design is used to compare pre-existing groups, such as children from divorced families versus those from non-divorced families, without manipulating any variables.

Question 10

Which kind of research uses a non-manipulated participant variable such as age or gender to define the groups being compared?

Accepted Answer

Differential research compares two or more pre-existing groups based on a non-manipulated participant variable such as age or gender. Time-series research involves measuring a variable repeatedly over time, one-group pretest-posttest research involves measuring a single group before and after an intervention, and pretest-posttest nonequivalent control group research involves comparing two groups that were not randomly assigned.

Question 11

The internal validity of the pre-post designs is threatened by

Accepted Answer

Pre-post designs are vulnerable to threats related to time, which may include maturation, regression to the mean, and history effects, among others. These threats may impact the internal validity of the study by leading to erroneous conclusions about the effectiveness of the intervention. Therefore, researchers must be vigilant in addressing these threats when designing and interpreting pre-post studies. Option B refers to threats related to differences between groups, which are a concern in experimental designs, but not in pre-post designs. Option C refers to differential effects or interactions between variables, which are also a concern in experimental designs, but not in pre-post designs. Option D is incorrect because only option A accurately describes the unique threats to pre-post designs.

Question 12

Which of the following is the correct classification for a posttest-only nonequivalent control group design?

Accepted Answer

The answer of Which of the following is the correct...

Question 13

Differential history effects are a threat to internal validity for which of the following designs?

Accepted Answer

Differential history effects are a threat to internal validity in pretest-posttest nonequivalent control group designs because different groups may experience different events between pretest and posttest, affecting the outcomes.

Question 14

One of the primary advantages of a pretest-posttest nonequivalent control group design,in comparison to other nonequivalent group designs,is

Accepted Answer

The pretest-posttest nonequivalent control group design is beneficial because the pretest scores can assist in reducing the threat of assignment bias. This design allows researchers to compare the pretest and posttest scores of both the experimental and control group. By doing this, researchers can evaluate the effect of an intervention or treatment, while also accounting for any pre-existing differences between the two groups. This design is useful for studying the effectiveness of an intervention in real-world settings where random assignment may not be feasible.

Question 15

Some threats to internal validity are related to time and other threats are related to differences between groups.Which of the following is a threat related to time?

Accepted Answer

History effects refer to events or changes that occur over time and might affect the outcome of the study, making it a threat related to time. Choice B (assignment bias) and choice C (differential history effects) are both related to differences between groups. Therefore, the correct answer is A.

Question 16

A researcher introduces a new mathematics program in one school district and uses a neighboring district as a no-treatment control group.Before the program begins,the students in both districts are given a standardized mathematics test.After the program is in place for 6 months,the students are tested again and the researcher compares the before and after scores for the two groups.This research study is classified as

Accepted Answer

This study is quasi-experimental because the researcher introduced a program to one group and used a neighboring group as a control, but did not have random assignment of participants to the groups.

Question 17

Last fall,a state college introduced a one-week study skills course for new freshmen students.At the end of the academic year,the college compared the grades and dropout rate for their freshmen with the corresponding measurements for freshmen at a neighboring state college.This study is an example of

Accepted Answer

The study compares outcomes between two groups (one with the intervention and one without) without random assignment, making it a posttest-only nonequivalent control group design.

Question 18

In nonexperiments and quasi-experiments different groups or conditions are defined in terms of

Accepted Answer

In nonexperiments and quasi-experiments, different groups or conditions are defined based on pre-existing participant variables or time, rather than the deliberate manipulation of an independent variable.

Question 19

In a typical pre-post study

Accepted Answer

In a typical pre-post study, one group is measured before and after a treatment to assess any changes that occur as a result of the treatment. Thus, the best choice is D.

Question 20

Which of the following is not an example of a nonexperimental or quasi-experimental study?

Accepted Answer

A study comparing performance in rooms with different wall colors involves manipulating an independent variable (wall color), making it an experimental study rather than nonexperimental or quasi-experimental.

Quiz 10: The Nonexperimental and Quasi-Experimental Strategies: Nonequivalent Group, Pre-Post, and Developmental Designs