Psychology 2020 Measurement & Observing Behavior

1. Psychology 2020 Measurement &Observing Behavior Unit 2

2. Measurement Reliability • Measurements consist of two components. Both must be inferred because they can’t be directly observed • True score • The real score of the variable that exists hypothetically and is considered a constant • Measurement error • The portion of the measurement result that varies from measurement to measurement • The higher the correlation (r near 1) between two measurements, the more reliable the measurement

3. Assessing the Reliability of Psychological Measures • Test-Retest Reliability • Take the measurement at two different times and correlate the results (r =.8 to be considered reliable). • Internal Consistency Reliability • Split test in half an correlate the scores on the first half with the scores on the second half • Correlate every item score with every other item score (Cronbach’s alpha) • Correlate every item score with the total score • Interrater Reliability • Correlate rater scores with each other

4. Validity in Research • Validity refers to “truth” and accuracy of measurement • INTERNAL validity (extent to which IV has influence on DV) • EXTERNAL validity (extent to which results obtained can be generalized) • CONSTRUCT validity • Several types

5. Measurement Validity • If a measurement tool is valid, it is really measuring the construct it purports to measure rather than some other characteristic • A valid measurement tool is said to have “Construct Validity”

6. Methods to Assess Construct Validity • Face Validity (does it appear valid) • An IQ test that only asked questions about a person’s income, address and clothing preferences would have little face validity • Criterion-Oriented Validity (does it allow accurate predictions) • A safe-driving test that passed people who continued to have driving accidents would lack criterion-oriented validity

7. Forms of Criterion-Oriented Validity • Predictive Validity- ability to predict something it should theoretically be able to predict. • A measure of math ability accurately predicts who will be a successful engineer • Concurrent Validity- ability to distinguish between groups that it should theoretically be able to distinguish between • A measure of anxiety distinguishes individuals with an anxiety disorder from those with major depression

8. Forms of Criterion-Oriented Validity • Convergent Validity- results from the measure are similar to other measures of the same construct • The block assembly IQ test yields high IQ scores with the same people who got high IQ scores on a spatial problem solving IQ test. • Discriminant Validity- results from the measure are NOT similar to measures of theoretically different constructs. • An abstract-reasoning test yields different results that a rote-memory test

9. Measurement Reactivity • Reactivity in measurement is when the very act of measuring a variable changes that variable • Example: recording the amount of food eaten each a day causes the person to eat less • Using unobtrusive measures reduces the probability of measurement reactivity

10. Measurement Scales

11. Measurement Scales • Nominal • No numerical properties, only named categories • Examples: male or female, married or single • Ordinal • Has numerical properties but only for the purpose of ordering the categories from first to last • Examples: Academic grades, places in a race, ranking schools or sports teams

12. Measurement Scales • Interval • Has numerical properties with equal distance between each number on the scale but no zero point (representing a total absence of the thing being measured). • Example: Rating beauty on a scale of 1-10 • Ratio • Same as the interval scale (equal intervals between numbers) except there is a zero point. • Examples: time measures, response rate measures, other physical measurements.

13. Name the Measurement Scale • A food critic rates restaurants according to the quality of food, service, and atmosphere. She assigns 4 forks for excellent, 3 for good, 2 for fair, and 1 fork for poor • Researchers have identified styles of leadership as relationship-oriented or task-oriented • Rating satisfaction on a scale of 1 to 100 • A measurement of weight

14. Name the Measurement Scale • Getting a count of the number of automobiles on the highway that were made in Europe, Japan and the USA (totals for each group) • The score you receive on the Beck Depression scale (1-18 is not depressed, above 18 is depressed) • Deciding if a house style is Victorian, Tudor, or Greek Revival • Measuring how long it takes someone to drink a beer

22. General Observational Approaches • Quantitative approaches • Emphasize numerical properties of the thing being observed • Observational results can be statistically analyzed • Examples • Hours spent studying • Ranking of task difficulty • Percentage of on-task behavior

23. General Observational Approaches • Qualitative approaches • Emphasizes the nonnumerical aspects of the thing being observed • Usually consists of descriptive paragraphs • Statistical analysis of data in this form is not possible • Examples • Diaries • Film documentaries • Written summaries of main themes and/or styles observed

24. Naturalistic Observation • Observing and recording behavior in its natural setting • Quantitative or qualitative • Confirmation through multiple observations

25. Issues in Naturalistic Observation • Participation • Concealment • Accuracy v. ethics • Scope of observation • Complexity • Limits of observation • Public v. private • Uncontrollable factors

26. Systematic Observation • Careful observation of specific behaviors in specific settings using structured, quantifiable methods (coding systems) • Statistical data analysis

27. Methodological Issues • Technical equipment (video tape, computers, clocks, etc.) • Reactivity • Reliability • Sampling

28. Video

29. Case Studies • Case studies are usually extensive descriptions of one individual or organization over a period of time. • Case studies are one form of naturalistic observation research • Case studies are conducted when an individual is unusual, has a rare disorder or noteworthy condition • Case studies provide valuable information that is not available in other forms of research

30. Archival Research • Archival research uses data that was previously collected and compiled (usually for other reasons) to answer new questions • Two problems exist for doing archival research • The necessary records or documents may be difficult to obtain • The accuracy of information collected by someone else is always suspect