Posttest Only Nonequivalent Groups Design

Pretest-Posttest Nonequivalent Groups Design

Interrupted Time-Series Design with Nonequivalent Groups

What is the defining characteristic of a nonequivalent groups design?

Because a nonequivalent groups design does not use random assignment, researchers must expect that their comparison groups will likely have pre-existing differences that could threaten the internal validity of their research.

A psychology researcher is investigating the effectiveness of a new 'Study Skills' seminar. Match each research scenario with the specific reason it constitutes a nonequivalent groups design.

Analyze the logical progression of how a nonequivalent groups design introduces threats to internal validity. Arrange the following steps in the correct order to show the relationship between the design choice and the resulting experimental confounding.

As a school psychologist, you are tasked with designing a study to evaluate whether a new 'Peer Mediation' program reduces playground conflict. If you are required to use a nonequivalent groups design, which of the following research plans should you develop?

A nonequivalent groups design is a type of between-subjects design where researchers do not use _____ assignment to allocate participants to conditions.

When evaluating whether a researcher can justify causal conclusions in a nonequivalent groups design, a critic would point out that the lack of random assignment fails to control for _____ variables, which serve as alternative explanations for the results.

A researcher compares a school that voluntarily implements a new mindfulness program with another school that does not. At the end of the year, students at the mindfulness school score significantly higher on a test of emotional regulation. True or False: Because this is a nonequivalent groups design, the researcher can confidently conclude that the mindfulness program caused the improvement in emotional regulation.

A researcher investigates a new teaching method by comparing two existing classrooms. Match each component of this nonequivalent groups design study with its corresponding analytical description.

Arrange the steps in the correct logical order to evaluate the validity of a researcher's causal claim in a study using a nonequivalent groups design.

Example of a Posttest Only Nonequivalent Groups Design

Pretest-Posttest Nonequivalent Groups Design

Controlling Confounds in a Posttest Only Nonequivalent Groups Design

Which of the following best describes a posttest only nonequivalent groups design?

In a posttest only nonequivalent groups design, researchers can confidently assume that the treatment caused any observed differences in the final outcomes.

A mental health researcher evaluates a new depression treatment by applying it to all patients at Clinic A and comparing them to patients at Clinic B who received standard care. Patients were not randomly assigned to the clinics. After six weeks, the researcher measures depression levels in both groups and expresses concern that Clinic A patients may have had higher baseline symptom severity than those at Clinic B. Match each element of this study to its corresponding role in the described research design.

A psychologist evaluates a new classroom intervention by applying it to one school and comparing the students' final test scores to those of a nearby school that did not use the intervention. No initial testing was conducted. Arrange the following steps in the logical sequence a researcher would use to analyze why this study fails to establish a clear cause-and-effect relationship.

A university researcher is tasked with planning a study to evaluate a new 'Mindfulness-Based Stress Reduction' (MBSR) elective for undergraduate students. The university administration allows the course to be offered to students in the Nursing program, while students in the Social Work program will not have access to it. However, the administration prohibits any baseline stress testing before the semester begins and forbids the random assignment of students between the two programs. Which of the following research plans correctly constructs a posttest only nonequivalent groups design to evaluate this intervention?

Match each component of the posttest only nonequivalent groups design with its correct description based on the concept definition.

A researcher evaluates a new mindfulness program by implementing it in one high school and comparing the students' final stress scores to those of a neighboring high school that did not use the program. If the researcher asserts that the program 'caused' the lower stress scores in the first school, a critical evaluator would reject this claim because the design fails to rule out the influence of _____.

A school psychologist compares the final exam reading scores of an existing third-grade class that received a new vocabulary curriculum with another existing third-grade class that did not. Because the classes are intact groups and students were not randomly assigned to them, this study is an application of a posttest only nonequivalent groups design.

In a posttest only nonequivalent groups design, the lack of random assignment when allocating participants means that any observed posttest differences may be caused by the treatment, but they could equally be the result of pre-existing _____ variables.

Order the steps involved in executing and evaluating a study using a posttest only nonequivalent groups design, from the initial setup to the final evaluation of internal validity.