Text reads Developmental psychologists use several research methods to study changes that occur with age. Imagine you want to know whether using social media helps protect against feelings of loneliness over time. How would you design a study measure that? Let’s compare methods.
Section 1: Longitudinal.
Text reads, measure a single group at different points in time.
Example: Researchers follow a sample of participants, interviewing them every decade for a total of three measurements. As they age, participants report lower levels of loneliness than expected. But because the study is longitudinal, we can’t eliminate the possibility that this particular group of participants is less lonely because of some historically specific effect.
A scale labeled Group 1 shows three different years with three different age groups. 2005- 20 years old; 2015- 30 years old; 2025- 40 years old.
Benefits: can track age-related changes.
Problems: measured changes could be specific to the particular group of participants. Takes a long time, leading some participants to drop out before study is complete.
Section 2: Cross-sectional.
Text reads, measure groups of people of different ages (for example, 20-, 40-, and 60-year-olds) at a single point in time.
Example: Researchers interview participants in three different age groups: 20-, 40-, and 60-year-olds. The oldest group reports higher levels of loneliness. But because the study is cross-sectional, we can’t be sure if this finding reflects a cohort effect, in which differences may be due to age or to common experiences within the group, as opposed to developmental changes in physical, cognitive, or socioemotional functioning.
A scale shows three years for different age groups. Group 1, 2005- 20 years old; group 2, 2015- 40 years old; Group 3, 2025- 60 years old.
Benefits: Allows comparison between age groups. Can be completed relatively quickly.
Problems: Susceptible to cohort effect.
Section 3: Cross-sequential.
Text reads, measure groups of people of different ages, following them across different points in time.
Example: Researchers interview participants from three age groups every decade for a total of three measurements. This results in data showing how social media use and loneliness change within each group as they age.
A scale shows three sets of three years for different age groups.
Group 1: 2005 - 20 years old, 2015 - 30 years old, 2025 - 40 years old.
Group 2: 2005 - 40 years old, 2015 - 50 years old, 2025 - 60 years old.
Group 3: 2005 - 60 years old, 2015 - 70 years old, 2025 - 80 years old.
Benefits: Shows changes within individuals and between groups. Better addresses cohort effect.
Problems: Requires substantial resources and many participants. Takes a long time, leading some participants to drop out before study is complete.