Control Group in Pretest-Posttest Designs

Strengths of Switching Replication

Which of the following best describes how instrumentation threatens a study's internal validity?

An instrumentation threat can occur even if the measurement process becomes more accurate over time, such as when a researcher gains skill in coding behaviors between the pretest and the posttest.

A clinical psychologist is conducting a six-month study on the effects of a new therapy. Match each scenario occurring between the pretest and posttest to the specific way it functions as an instrumentation threat to internal validity.

A developmental psychologist is studying the impact of a 'kindness curriculum' on playground behavior. Analyze how an instrumentation threat leads to a false conclusion by ordering the events of the study from the initial measurement to the final logical error.

An instrumentation threat to internal validity can occur if participants change their approach to a measurement tool, such as becoming bored or less careful with their responses, between the pretest and the posttest.

A developmental psychologist measures 'cooperative play' in toddlers using a specific behavioral checklist. If the psychologist becomes significantly more skilled at spotting these behaviors by the time of the posttest, the resulting data suffers from an instrumentation threat because:

A senior researcher is evaluating a peer's study on classroom aggression. They notice that the observers were extremely strict during the pretest but became fatigued and more lenient by the posttest, leading to a recorded 'decrease' in aggression that likely does not exist. The researcher rejects the study's conclusions, judging that the measurement standards shifted over time. To justify this critique of the study's internal validity, the researcher would cite a(n) _____ threat.

A clinical psychologist is evaluating a new mindfulness program and administers a psychological survey before and after the intervention. Match each scenario describing a change in the measurement process to the type of instrumentation threat it represents.

An educational psychologist measures classroom engagement. In the pretest, the observers are fresh and strict, but in the posttest, they are tired and lenient, which changes the measurement standards. In this research design, the internal validity is compromised specifically by the threat of _____.

A researcher is evaluating a school program. Order the events to show how an undetected instrumentation threat leads a researcher to draw an invalid evaluative conclusion about a program's effectiveness.

Define instrumentation as a threat to internal validity and describe the two primary ways this threat can manifest in a study (specifically regarding the roles of observers and participants) according to the provided text.

Explain how observer fatigue in this scenario represents an instrumentation threat to internal validity, and explain why the psychologist cannot conclude that the sharing intervention was successful based on these results.

A clinical researcher administers a long, repetitive questionnaire about anxiety levels before and after a mindfulness program. Apply the concept of instrumentation to explain how the participants' own motivation or attention span during the posttest could introduce this threat.