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Research Methods in Psychology Second Edition. Lecture Slides by Dana B. Narter, Ph.D. Three Claims, Four Validities: Interrogation Tools for Consumers of Research. Chapter 3. Chapter Overview. Variables Three claims Interrogating the three claims using the four big validities
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Research Methods in PsychologySecond Edition Lecture Slides by Dana B. Narter, Ph.D.
Three Claims, Four Validities: Interrogation Tools for Consumers of Research Chapter 3
Chapter Overview • Variables • Three claims • Interrogating the three claims using the four big validities • Prioritizing validities
Variables • Variables vs. constants • Measured and manipulated variables • From conceptual variable to operational definition
Measured and Manipulated Variables • Measured variables are observed and recorded. • Manipulated variables are controlled. • Some variables can only be measured—not manipulated. • Some variables can be either manipulated or measured.
Three Claims • Frequency claims • Association claims • Causal claims • Not all claims are based on research.
Frequency Claims • Frequency claims describe a particular rate or degree of a single variable. • Frequency claims involve only ONE MEASURED VARIABLE.
Association Claims • Association claims argue that one level of a variable is likely to be associated with a particular level of another variable. • Association claims involve at least TWO MEASURED VARIABLES. • Variables that are associated are correlated.
Making Predictions Based On Associations • Some association claims are useful because they help us make predictions. • The stronger the association between the two variables, the more accurate the prediction. • Both positive and negative associations can help us make predictions, but zero associations cannot.
Not All Claims Are Based On Research • Not all claims we read about in the popular press are based on research. • Some claims are based on experience, intuition, or authority.
Interrogating the Three Claims Using the Four Big Validities • Interrogating frequency claims • Interrogating association claims • Interrogating causal claims
Interrogating Frequency Claims • Construct validity • External validity (generalizability) • Statistical validity
Interrogating Association Claims • Construct validity • External validity • Statistical validity
Statistical Validity of Association Claims • Strength and significance • Avoiding two mistaken conclusions • Type I error • Type II error
Table 3.5: Interrogating the Three Types of Claims Using the Four Big Validities
Interrogating Causal Claims • Three criteria for causation • Covariance • Temporal precedence • Internal validity
Experiments Can Support Causal Claims • Experiment • Independent variable • Dependent variable • Random assignment
When Causal Claims Are A Mistake • Do family meals really curb eating disorders? • Do early language skills reduce preschool tantrums?
Other Validities To Interrogate In Causal Claims • Construct validity • External validity • Statistical validity
Prioritizing Validities • Which of the four validities is the most important? • It depends on what kind of claim the researcher is making and what her priorities are.
This concludes the Lecture Slides for Chapter 3 Research Methods in Psychology Second Edition by Beth Morling For more resources to accompany this text, see wwnorton.com/instructors and everydayresearchmethods.com.