Learn Before
Briefly describe the primary concern with focusing exclusively on group means in data analysis, and explain how a treatment can impact every participant while still appearing to have no effect.
Question: Briefly describe the primary concern with focusing exclusively on group means in data analysis, and explain how a treatment can impact every participant while still appearing to have no effect.
Sample answer: The primary concern is that group means can obscure important individual differences among participants. A treatment can seem to have no effect if it produces a strong positive effect on half of the participants and an equally strong negative effect on the other half. When the average is calculated, these opposing outcomes statistically cancel each other out, making the treatment group's mean identical to the control group's mean.
Key points:
- Focusing exclusively on group means obscures important individual differences.
- A treatment might have a strong positive effect on half the participants.
- The same treatment might have an equally strong negative effect on the other half.
- Opposing effects statistically cancel each other out, resulting in a mean that looks identical to a control group.
Rubric: Full credit is given for explicitly recalling that group means obscure individual differences and for providing the explanation of opposing positive and negative effects canceling each other out statistically.
0
1
Tags
KPU
Research Methods in Psychology - 4th American Edition @ KPU
Related
Observing Individual Effects in Group Research
Examining Individual Distributions in Group Research
What is a major concern when researchers focus exclusively on group means to analyze the effects of a treatment?
True or False: If a psychological intervention produces a large positive effect in half of a study's participants and an equally large negative effect in the other half, comparing the treatment group's mean to the control group's mean will reliably reveal that the intervention had a strong impact.
A psychologist is evaluating a new cognitive training task designed to improve memory performance. Arrange the following steps in the correct order to demonstrate how focusing on the group mean can lead to a misleading conclusion about the task's effectiveness.
An educational psychologist finds that a new teaching method results in a treatment group mean identical to the control group mean. To analyze how this average might misrepresent the actual data, match each individual data pattern with its corresponding analytical implication.
If a psychological treatment produces a strong positive effect on half of the participants and an equally strong negative effect on the other half, these opposing effects will statistically cancel each other out when calculating the group mean.
A researcher observes that the mean outcome score of a treatment group is identical to the mean outcome score of a control group. Based on the concept of misleading group means, why might it be premature to conclude that the intervention had absolutely no impact on the participants?
A researcher evaluates a new therapeutic method and concludes it is 'ineffective' because the average outcome for the treatment group was identical to the control group. However, if the therapy actually caused significant improvements for half of the participants and significant declines for the other half, the researcher's conclusion is _____ because the group mean obscures these opposing effects by allowing them to cancel each other out.
An educational psychologist administers a reading intervention. In the treatment group, some students improve drastically while others regress. To identify how group averages can obscure these results, match each scenario concept to the description of its manifestation in the study.
When analyzing data in a group research design, focusing exclusively on group means can obscure important individual differences because opposing participant outcomes can statistically _____ each other out.
Evaluate how a researcher could mistakenly conclude that a highly active drug is completely ineffective. Order the sequence of events showing how relying solely on group means leads to this erroneous conclusion.
Briefly describe the primary concern with focusing exclusively on group means in data analysis, and explain how a treatment can impact every participant while still appearing to have no effect.
Based on the limitations of an exclusive focus on group averages, explain why the researcher's conclusion might be false. Describe the specific individual differences that could be hidden within the treatment group's average score of 50.
A clinical psychologist evaluates a new anti-anxiety drug. The treatment group's mean anxiety score is identical to the placebo group's mean. Apply the concept of misleading group means to explain how the drug could still be considered highly active for every single participant.