AS Level Psychology (9990) Case Studies Practice Exam

Dreaming was studied in a sleep lab with tight control over the environment and procedures. Researchers used EEG to identify precisely when someone was in REM sleep and then woke participants at specific times to collect dream reports. This clear manipulation of the sleep condition (awakening during REM versus non-REM) and the systematic measurement of the outcome (whether a dream could be recalled and its content) show a laboratory experiment design. The setting and methods reduce extraneous influences and allow a cause-and-effect relationship between sleep stage and dream recall to be tested, with repeated measures across nights strengthening the comparison within the same individuals. It isn’t a cross-sectional survey, since it isn’t gathering one-off data from a population; it isn’t grounded theory, since it isn’t generating theory from qualitative data; and it isn’t a longitudinal cohort, since it doesn’t follow people over long periods in their daily lives.