Research Methods- Chapter 14
Differences between longitudinal, cross-sectional, and cohort-sectional designs
The primary difference is how age is treated as a variable Longitudinal: Behavior compared at different ages for a single group of participants over time Cross-sectional: Behavior is compared for different groups of participants of different ages Cohort-sectional: Different groups of participants of different ages (cohorts) are tester over time to see a change in behavior for each group as they age
Generation/cohort effects
A confound that can occur in cross-sectional designs due to different experiences that different generations have
Longitudinal designs
A developmental design where a single sample of participants is followed over time and tested at different ages
Cross-sectional design
A developmental design where multiple samples of participants of difference ages are tested at once
Cohort-sequential design
A developmental design where multiple samples of participants of different ages are followed over time and tested at different ages
Explain the role small-n designs play in psychological research
Allows psychologists to test laws of behavior and to test treatments that might be effective for a single patient or a small group of participants
Why do developmental psychologists need specialized designs?
Allows them to examine different types of age effects in a study... Because age cannot be manipulated, many of these designs are quasi-experiments that compare age
Within subjects variable
Each participant experiences all levels of the IV
Developmental designs
Longitudinal Cross-sectional Cohort-sequential
Testing effects
Occur when participants are tested more than once in a study, with early testing affecting later testing
Attrition/mortality in relation to longitudinal designs
Occurs when participants choose not to complete a study May occur with longitudinal design studies because participants might get tired of being in the study, or move and lose touch with the researchers
