types of psychological research. 193050607080 194040506070 195030405060 196020304050...
TRANSCRIPT
Types of Psychological
Research
1930 50 60 70 80
1940 40 50 60 70
1950 30 40 50 60
1960 20 30 40 50
1980 1990 2000 2010
Time of Measurement
Co
ho
rt
1930 50 60 70 80
1940 40 50 60 70
1950 30 40 50 60
1960 20 30 40 50
1980 1990 2000 2010
1 Column = Cross-Sectional Study
Controlled = Time of MeasurementConfounded/Extraneous = Age & Cohort
Advantages• Cost Effective• Easy to Manage/Time Effective
Disadvantages• Cannot Assess Individual Development• Nothing Learned about Continuity of Dev.• Cohort Effects*** (Grand Assumption)
1930 50 60 70 80
1940 40 50 60 70
1950 30 40 50 60
1960 20 30 40 50
1980 1990 2000 2010
1 Row = Longitudinal Study
Controlled = CohortConfounded/Extraneous = Age & Time of Measure
Advantages• Same Individuals/Individual Development• Only Way to Answer “Stability/Instability”
Disadvantages• Costly• Time Consuming/Labor Intensive• Difficulty in Maintaining Contact• Focus of Theory/Research May Change• Drop-Outs/Deaths (Including Researcher)• Selective Attrition/Non-Rep. Sample (Bias)• Practice Effects/Test Familiarity• Cross-Generational Problem
Cross-Sectional Question:Do 70-year-olds hold more conservative gender-role attitudes than 30-year-olds because they are older or because they are members of a different cohort raised in a more traditional period?
Longitudinal Question:Are there responses in 2000 more liberal than 1960 because gender-role attitudes become more liberal with age or because major societal changes occurred from one time of measurement to the next?
Cross-Sectional Question:When giving intelligence tests to representative samples of people, researchers consistently find that older adults give fewer correct answers than do younger adults. Why is this? Is it there age, or there cohort?
Longitudinal Question:When the same people are retested over a series of years, intelligence remains stable, until late in life. Is the stability of intelligence attributable to age or societal advances at the time of measurement?
The Best of Both Worlds
They can tell researchers:
Which age-related trends are truly developmental in nature and reflect how most people, regardless of cohort, can be expected to change over time (age effects).
Which age-trends differ from cohort to cohort and suggest that each generation is affected by its distinct growing-up experiences (cohort effects).
Which trends suggest that events during a specific period similarly affect all cohorts alive at the time (time of measurement effects).
Sequential Designs Untangle the Effects of Sequential Designs Untangle the Effects of AgeAge, , CohortCohort, & , & Time of MeasurementTime of Measurement & Indicate & Indicate Which Age Trends Are Truly Developmental in Nature.Which Age Trends Are Truly Developmental in Nature.
