Questions and Answers
Which of the following are ways to measure variables? (Select all that apply)
What is a self-report measure?
Operationalizes a variable by recording people's answers to questions about themselves in a questionnaire or interview.
What does an observational measure do?
Operationalizes a variable by recording observable behaviors or physical traces of behaviors.
What is a physiological measure?
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What are the scales of measurement? (Select all that apply)
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What defines categorical variables?
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Describe quantitative variables.
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What are the three types of quantitative variables?
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What is an ordinal scale?
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What does the interval scale indicate?
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What is a ratio scale?
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What does reliability refer to in the context of measurement?
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What is validity concerned with?
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Which of the following are types of reliability? (Select all that apply)
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What does test-retest reliability measure?
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What is interrater reliability?
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What does internal reliability (or internal consistency) ensure?
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What is Cronbach's alpha used for?
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Define construct validity.
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What does measurement validity reflect?
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What is the difference between reliability and validity?
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What is face validity?
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What is criterion validity based on?
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What is the known groups paradigm?
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Define convergent validity.
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Define discriminant validity.
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Can a measure be reliable but not valid?
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Study Notes
Ways to Measure Variables
- Three primary measurement methods: self-report, observational, and physiological.
Self-Report Measure
- Gathers data by having individuals answer questions in surveys or interviews.
- Commonly measures personal attributes like gender, stress, religiosity, motivation, and personality.
Observational Measure (Behavioral Measure)
- Captures data by noting observable actions or traces from behaviors.
- Examples include assessing intelligence through puzzle-solving or measuring happiness by counting smiles.
Physiological Measure
- Involves recording biological indicators such as brain activity, hormone levels, or heart rate.
- Techniques include fMRI for brain scanning and facial EMG to detect muscle movements indicating emotions.
Scales of Measurement
- Two main categories: categorical and quantitative variables.
Categorical Variables
- Comprise discrete categories with no numerical meaning, such as gender or species.
- Coded arbitrarily, e.g., 1 for Male and 2 for Female.
Quantitative Variables
- Represent measurable quantities with meaningful numerical values, such as height or test scores.
Types of Quantitative Variables
- Ordinal scale: ranks order without indicating difference degree.
- Interval scale: equal intervals with no true zero, e.g., IQ scores or temperature.
- Ratio scale: possesses equal intervals and a true zero, e.g., height or time measurements.
Reliability
- Indicates the consistency of measurement results.
Validity
- Evaluates whether the measurement accurately reflects the intended variable.
Types of Reliability
- Test-retest reliability: Consistency across multiple uses of the same measure.
- Interrater reliability: Consistency regardless of who conducts the measurement.
- Internal reliability: Consistency of responses among related items within a measure.
Evaluating Reliability with R
- Positive correlation (r > 0.5) indicates strong test-retest reliability.
- Interrater reliability evaluated with an ideal positive correlation (r > 0.7).
Measuring Internal Reliability
- Assessed by the association among items meant to evaluate the same construct, using Cronbach's alpha.
Cronbach's Alpha
- A correlation metric used to examine the internal reliability of measures.
Construct Validity
- Integrates both measurement reliability and validity.
Measurement Validity
- Reflects how effectively a measure represents the intended construct, e.g., assessing self-reported religiosity accuracy.
Reliability vs. Validity
- Reliability focuses on consistency, while validity emphasizes accuracy; a measure can be reliable yet not valid.
Valid Measures of Abstract Constructs
- Psychologists may operationalize concepts like happiness through varied methods: questionnaires, observation, or biological indicators.
Face Validity
- Subjective assessment indicating whether a measure seems plausible; e.g., head circumference as an indicator of hat size appears valid but not for IQ.
Content Validity
- Ensures that the measure encompasses all facets of the construct being evaluated.
Criterion Validity
- Validity assessed through empirical evidence showing correlation with key outcomes, exemplified by the relationship between SAT scores and college GPA.
Known Groups Paradigm
- Evaluates if a measure differentiates between groups with already understood behavior.
Convergent Validity
- Measures of the same construct should correlate strongly with each other.
Discriminant Validity
- A measure should exhibit weaker correlations with different but related constructs.
Reliability and Validity Relationship
- A precise measure can be reliable without being valid; however, validity cannot exceed reliability levels.
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Description
Explore the key concepts of measurement in psychology through flashcards. This quiz covers self-report, observational, and physiological measures, essential for understanding how to quantify and analyze variables effectively.