Lecture 5 Flashcards
Cross-sectional design
Measuring at different ages
Cohort effects
Variations over time among groups of individuals defined by some shared experience
Longitudinal design
Measuring the same children at different ages
Things we don’t know after cross-sectional study
- Are differences stable over time
- Why do differences arise
- What is the curve of development
No association between moments of measurement problems
- No measurement equivalence
- Too much noise in measurements
- No stability of the measured construct
Strong aspects of longitudinal design
- Effects cannot be attributed to cohort differences
- Association between measurements at different ages
- Individual curves of development
Weak aspects of longitudinal design
- Expensive
- Waiting long time for results
- Dropout of subjects
- Different measurement instruments
- Possible practice effects
- Not always possible to generalize to other cohorts
Sequential design
Uses cohort, cross-sectional and longitudinal comparisons
Finding evidence for causality without experimentation
Matching of groups and partial correlations
When are observational methods used
When people cannot reliably complete questionnaires
Downsides of observational methods
- Selectivity
- Subjectivity
- Absence of base rate
- Stability of perception
Molecular and Molar
Molecular is very objective
Molar is more about interpretation
Reasons for measuring IQ
- Diagnosis of learning problems
- Diagnosis of cognitive problems
- School choice
Visual cliff
Fear of depth develops after 6 weeks of crawling
Visual preference method
Infants show systematic preferences for faces, complex and new stimuli
