PSY 2114 Chapter Notes - Chapter 2: Selection Bias, Cell Division, Zygote

• School: University of Ottawa
• Department: Psychology
• Course: PSY 2114
• Professor: Wendy Lee

Document Summary

In experiments it is possible to make inferences about causes and effects. Longitudinal is done to study changes with time/age while cross-sectional is done to make inferences about age differences. Longitudinal is based on one cohort while cross-sectional uses different cohorts. Cohorts are certain trends that apply to certain age groups or cohorts but not to others. This makes it difficult to generalize results to larger groups. Cohorts are a bigger problem in cross-sectional studies. Because cross-sectional studies require different age groups and thus, different cohorts and this makes it difficult to compare effects of development among these cohorts. Selective attrition is the tendency of some people to drop out of studies over time. This can be a problem if the people who leave the experiment are very different from the group that remains, leading to attrition bias. Sequential designs provide a combination of both longitudinal and cross-sectional designs.