Scenario
Dr. Al Ert learned that elderly people tend to experience fewer dementia symptoms when they have daily tasks that they are responsible for remembering. Dr. Al Ert wondered whether the type of daily task affected their memory skills. He recruited 100 participants who were
65-years-old and randomly assigned half of the participants to water plants and the other half to check the mail. Participants were told to continue doing their assigned task every day, and Dr. Al Ert tested them all on the same memory test at 3 different time points: once when they were 65 years old, again when they were 70 years old, and again when they were 75 years old. He analyzed the data to determine whether age and daily task type affected memory skills.
4
Multiple Choice 3 points
Because Dr. Al Ert studied the effect of age using a
design, any differences he finds
across different ages may be influenced by
effects.
cross-sectional; mortality longitudinal; mortality cross-sectional; cohort
sequential; both cohort and mortality longitudinal; cohort