Questions and Answers
What is an observational study?
An observational study measures the value of the response variable without attempting to influence the value of either the response or explanatory variables.
What is a designed experiment?
A designed experiment is when a researcher assigns individuals to a certain group, intentionally changing the value of an explanatory variable, and then recording the value of the response variable for each group.
Which allows the researcher to claim causation between an explanatory variable and a response variable?
Designed experiment
What is meant by confounding?
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What is a lurking variable?
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What is a confounding variable?
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What is a cross-sectional study?
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What is a case-control study?
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Which is the superior observational study, a cross-sectional study or a case-control study?
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What does it mean when an observational study is retrospective?
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What does it mean when an observational study is prospective?
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Is the study of the relationship between skin cancer and hair color an observational study or an experiment?
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Is the study with fifty patients with colon cancer receiving an experimental drug an observational study or an experiment?
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Is the study of heart arrhythmias and caffeine consumption observational or experimental?
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Is the study dividing athletes into training groups observational or experimental?
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Is the study comparing two teaching methods in eighth-grade students observational or experimental?
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What is the implication of the second-grade students' poll conducted by the English department?
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Study Notes
Observational Studies vs. Designed Experiments
- An observational study measures response variables without influencing the explanatory variables.
- A designed experiment manipulates an explanatory variable through group assignment, allowing for causation claims between variables.
Confounding and Variables
- Confounding occurs when effects of multiple explanatory variables are mixed, obscuring relationships with the response variable.
- A lurking variable is an unaccounted explanatory variable influencing the response variable, often related to other variables in the study.
- A confounding variable is recognized in the study, but its effects cannot be separately identified from another explanatory variable.
Types of Observational Studies
- Cross-sectional studies capture information about individuals at a specific moment or brief time period.
- Case-control studies are retrospective and require looking back in time or reviewing existing records, providing insights into past conditions or exposures.
Retrospective vs. Prospective Studies
- Retrospective studies rely on individuals or researchers examining past data.
- Prospective studies involve data collection over time, tracking outcomes as they happen.
Identifying Study Types
- A study examining skin cancer and hair color is an observational study, as it records data without influencing responses.
- A study with colon cancer patients receiving an experimental drug versus a placebo is an experiment, controlling variables to measure outcomes.
- A survey of caffeine consumption in heart arrhythmia patients is an observational study, simply collecting data without manipulation.
- An experiment involving randomly divided athletes comparing weight resistance and cardio training is an experiment, as it controls training methods to assess fitness outcomes.
- A math proficiency study comparing teaching methods among eighth graders is an experiment, due to controlled variable manipulation to measure the effect.
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Description
This quiz focuses on key concepts in statistics, particularly observational studies and designed experiments. You will explore definitions and differences that allow researchers to establish causation. Test your understanding with these flashcards!
