Читать книгу Lifespan Development - Tara L. Kuther - Страница 92

A sequential research design combines the best features of cross-sectional and longitudinal research by assessing multiple cohorts over time, enabling scientists to make comparisons that disentangle the effects of cohort and age (see Table 1.7). Consider the alcohol use study once more. A sequential design would begin in 2020 with a survey to students ages 12, 14, 16, and 18. Two years later, in 2022, the initial sample is surveyed again; the 12-year-olds are now 14, the 14-year-olds are now 16, and the 16-year-olds are now 18. The 18-year-olds are now 20 and are not assessed because they have aged out of the study. Now a new group of 12-year-olds is surveyed. Two years later, in 2024, the participants are surveyed again, and so on.

A sequential design combines cross-sectional and longitudinal designs, permitting the researcher to study multiple cohorts over time.

Table 1.7

Source: Adapted from Kim & Böckenholt (2000) Psychological Methods, Vol 5(3), Sep 2000, 380-400.

Table 1.8

The sequential design provides information about age, cohort, and age-related change. The cross-sectional data (comparisons of 12-, 14-, 16-, and 18-year-olds from a given year) permit comparisons among age groups. The longitudinal data (annual follow-up of participants ages 12 through 18) permit helps scientists separate cohort effects from age-related change. Because several cohorts are examined at once, the effect of cohort can be studied. The sequential design is complex, but it permits human development researchers to disentangle the effects of age and cohort, as well as answer questions about developmental change.

In summary, scientists use the scientific method to systematically ask and seek answers to questions about human development. Researchers’ decisions about measures and research designs influence the information that they collect and the conclusions that they make about development. Researchers have responsibilities to conduct sound research and also to adhere to standards of ethical conduct in research, as the next section describes. See Table 1.8 for a comparison of research designs.