Читать книгу Lifespan Development - Tara L. Kuther - Страница 91

A longitudinal research study follows the same group of participants over many points in time. Returning to the previous example, to examine how alcohol use changes from 12 to 18 years of age, a developmental scientist using longitudinal research might administer a survey on alcohol use to 12-year-olds and then follow up 2 years later when they are 14, again when they are 16, and finally when they are 18. If a researcher began this study in 2020, the last round of data collection would not occur until 2026.

Longitudinal research provides information about age change because it follows people over time, enabling scientists to describe how the 12-year-olds’ alcohol use changed as they progressed through adolescence. However, longitudinal research studies only one cohort, calling into question whether findings indicate developmental change or whether they are an artifact of the cohort under study. Was the group of 12-year-olds that the scientist chose to follow for 6 years somehow different from the cohorts or groups of students who came before or after? Because only one cohort is assessed, it is not possible to determine whether the observed changes are age-related changes or changes that are unique to the cohort examined.