Interrupted Time-Series Design

Control Group in Pretest-Posttest Designs

History as a Threat to Internal Validity

Maturation as a Threat to Internal Validity

Testing as a Threat to Internal Validity

Instrumentation as a Threat to Internal Validity

Regression to the Mean as a Threat to Internal Validity

Spontaneous Remission

Example of a One-Group Pretest-Posttest Design

Why is it difficult to conclude with certainty that a treatment was effective when using a one-group pretest-posttest design?

A researcher is using a one-group pretest-posttest design to study the effect of a new stress-reduction workshop on college students. Match each component of the study to its specific role in this research design.

A health psychologist wants to evaluate the impact of a weekend nature retreat on stress levels using a one-group pretest-posttest design. Arrange the steps of this study in the correct chronological order.

A researcher evaluates a new study-skills workshop using a one-group pretest-posttest design and observes a significant increase in students' grade point averages at the end of the semester. The researcher can definitively conclude that the workshop caused the increase because the pretest measurement successfully accounts for each participant's individual academic history.

Which of the following describes the basic procedure used in a one-group pretest-posttest design?

A researcher evaluates a new social-anxiety intervention using a one-group pretest-posttest design and finds that participants' anxiety levels are lower at the posttest than they were at the start. When appraising the scientific merit of the claim that 'the intervention caused the change,' a peer reviewer would note that the lack of a comparison group makes it impossible to rule out threats like maturation or history. Consequently, in terms of research design standards, this study is evaluated as having critically low _____ validity.

When using a one-group pretest-posttest design to evaluate a new mindfulness intervention, the researcher uses the pretest to establish a(n) _____ for participants' stress levels before the intervention occurs.

A researcher evaluates a new math tutoring software using a one-group pretest-posttest design. To control for potential order effects, the researcher can counterbalance the study by having half of the participants take the posttest exam before they use the tutoring software.

Analyze the structural differences between a within-subjects experiment and a one-group pretest-posttest design. Match each design characteristic to the research design or feature it describes.

An educational psychologist wants to evaluate the effectiveness of a new reading intervention using a one-group pretest-posttest design. Arrange the steps of the research process and the subsequent evaluation of its findings in the correct chronological and logical order.