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Questions and Answers
What aspect does maturation primarily focus on in the context of group behavior changes?
What aspect does maturation primarily focus on in the context of group behavior changes?
Which of the following describes the purpose of a comparison group in an experimental study?
Which of the following describes the purpose of a comparison group in an experimental study?
What can be inferred if a group shows improvement simply due to maturation?
What can be inferred if a group shows improvement simply due to maturation?
How does history as a factor influence experimental outcomes?
How does history as a factor influence experimental outcomes?
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Why might air conditioning in November affect a comparison group's results?
Why might air conditioning in November affect a comparison group's results?
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What is a primary internal validity threat discussed in the content?
What is a primary internal validity threat discussed in the content?
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What phenomenon can be specifically categorized as a maturation threat?
What phenomenon can be specifically categorized as a maturation threat?
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Which of the following changes helps reduce maturation threats in experiments?
Which of the following changes helps reduce maturation threats in experiments?
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Which internal validity threat could lead researchers to misinterpret improvements in an experiment?
Which internal validity threat could lead researchers to misinterpret improvements in an experiment?
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What type of experimental design is suggested to avoid the issues associated with one-group designs?
What type of experimental design is suggested to avoid the issues associated with one-group designs?
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Which of these threats does NOT typically apply to one-group pretest/posttest designs?
Which of these threats does NOT typically apply to one-group pretest/posttest designs?
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A researcher notes that a participant’s depressive symptoms decreased over time. What could be a possible explanation for this besides treatment?
A researcher notes that a participant’s depressive symptoms decreased over time. What could be a possible explanation for this besides treatment?
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Which of the following is NOT mentioned as a potential internal validity threat?
Which of the following is NOT mentioned as a potential internal validity threat?
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What is the primary purpose of using a comparison group in studies like those conducted by Nikhil and Dr. Yuki?
What is the primary purpose of using a comparison group in studies like those conducted by Nikhil and Dr. Yuki?
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What would be an example of a history threat in the studies discussed?
What would be an example of a history threat in the studies discussed?
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In the Go Green campaign study, what would indicate a history effect rather than an impact from the campaign itself?
In the Go Green campaign study, what would indicate a history effect rather than an impact from the campaign itself?
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How can pretest/posttest design help in controlling for maturation and history threats?
How can pretest/posttest design help in controlling for maturation and history threats?
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What type of threat might arise if an external event coincides with the treatment, affecting participants' responses?
What type of threat might arise if an external event coincides with the treatment, affecting participants' responses?
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Which of the following is NOT a characteristic of a history threat?
Which of the following is NOT a characteristic of a history threat?
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In the context of the studies described, what primary benefit does a comparison group provide?
In the context of the studies described, what primary benefit does a comparison group provide?
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Why might the low-sugar diet not be the sole explanation for the campers' improved behavior?
Why might the low-sugar diet not be the sole explanation for the campers' improved behavior?
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What is a primary method to prevent instrumentation threats in research?
What is a primary method to prevent instrumentation threats in research?
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Which of the following best describes an instrumentation threat?
Which of the following best describes an instrumentation threat?
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In a posttest-only design, how is the behavior of participants measured?
In a posttest-only design, how is the behavior of participants measured?
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What can result in a selection-history threat during a study?
What can result in a selection-history threat during a study?
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Why might selection-attrition threaten the validity of an experiment?
Why might selection-attrition threaten the validity of an experiment?
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How can Dr. Yuki control for different test forms during her experiment?
How can Dr. Yuki control for different test forms during her experiment?
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Which statement differentiates between testing threats and instrumentation threats?
Which statement differentiates between testing threats and instrumentation threats?
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What might be an effect of a comparison group undergoing construction during a study?
What might be an effect of a comparison group undergoing construction during a study?
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What is regression to the mean typically observed in an experimental group with extreme pretest scores?
What is regression to the mean typically observed in an experimental group with extreme pretest scores?
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How does attrition affect the observed results in an experimental study?
How does attrition affect the observed results in an experimental study?
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What aspect of an experimental design is critical for validating outcomes under extreme conditions?
What aspect of an experimental design is critical for validating outcomes under extreme conditions?
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What is a likely outcome if the most extreme cases in an experiment drop out?
What is a likely outcome if the most extreme cases in an experiment drop out?
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In an experiment assessing the GRE verbal scores, what would indicate an order effect?
In an experiment assessing the GRE verbal scores, what would indicate an order effect?
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What characteristic of random events is essential for understanding regression to the mean?
What characteristic of random events is essential for understanding regression to the mean?
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What happens when researchers compute scores only including final samples in their analysis?
What happens when researchers compute scores only including final samples in their analysis?
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In a scenario where participation leads to positive outcomes, what is a key consideration for the researchers?
In a scenario where participation leads to positive outcomes, what is a key consideration for the researchers?
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Study Notes
Internal Validity Threats
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Maturation threats: Changes in behavior occur over time naturally, not due to the intervention.
- Example: Campers' behavior improves due to settling in, not the low-sugar diet.
- Prevention: Use a comparison group with similar characteristics that do not receive the intervention.
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History threats: An external event affects the treatment group, making it unclear if the change is due to the intervention or the event.
- Example: Dorm residents reduce electricity usage due to cooler weather, not a Go Green campaign.
- Prevention: Use a comparison group that does not receive the treatment, but experiences the same external event.
-
Regression threats: Extreme scores tend to regress towards the mean on subsequent measurements.
- Example: A group with very low scores at pretest may improve simply due to regression towards the mean, not the intervention.
- Prevention: Use a comparison group that started with similar extreme scores but didn't receive the intervention.
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Attrition threats: Participants drop out of the study, potentially affecting the results.
- Example: Participants in a depression therapy study drop out, leading to an unclear conclusion on the effectiveness of the intervention.
- Prevention: Use a comparison group, and ensure that the dropouts are similar in both groups.
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Testing threats: Repeated testing can influence participants' scores at posttest, making it unclear if the change is due to the intervention or familiarity with the test.
- Example: Students taking a GRE verbal test may perform better at posttest due to familiarity with the test, not the intervention.
- Prevention: Use a comparison group taking the same tests, or use a post-test only design.
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Instrumentation threats: Changes in the measuring instrument itself can lead to differences in posttest scores.
- Example: Different forms of a test might have varying difficulty levels, influencing the results.
- Prevention: Use the same instrument for both pretest and posttest, or counterbalance the forms.
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Combined threats: Selection threats can combine with history or attrition threats.
- Example: One dorm has access to construction equipment, impacting electricity usage, making it unclear if it's due to the Go Green campaign or the equipment.
- Prevention: Ensure groups are similar in terms of potential confounding variables, such as access to external events or participant characteristics.
Other Threats
- Observer bias: Researchers' expectations may influence their observations.
- Demand characteristics: Participants may change their behavior based on their perception of the study's purpose.
- Placebo effects: Participants may experience real effects due to their belief in the intervention, even if the intervention is not effective.
Key Takeaways
- One-group, pretest/posttest designs are vulnerable to several internal validity threats.
- True pretest/posttest designs (with at least two groups) can help control for many internal validity threats.
- Using comparison groups is crucial to rule out alternative explanations and measure the true effectiveness of the intervention.
- Understanding and addressing these threats are crucial for ensuring the validity and reliability of research findings.
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Description
Explore the various threats to internal validity in research, including maturation, history, and regression threats. This quiz will help you identify examples and prevention strategies to mitigate these threats in experimental designs. Test your understanding of how external factors can influence research outcomes.
