PSYB01H3 Chapter Notes - Chapter 8: Cognitive Psychology, Selection Bias, Longitudinal Study
Document Summary
When particular individual characteristics are used for the bases of selecting research participants, an experimenter is often interested in studying the effects of these subject variables on a dependent measure. When exposures to events, situations, or settings that emanate from the real world define how participants are selected, we refer to this type of independent variable as a natural treatment. In studies of the effects of a natural treatment on a dependent variable, exposure and non- exposure would form two levels of the independent variable. Subject variables and natural treatments belong to a distinct class of independent variables that many behavioural researchers term quasi-independent . Quasiexperiments offer a fertile research design for investigating some of the most important and creative questions in psychology. Nonequivalent-control-group designs have experimental and comparison groups that are designated before the treatment occurs and are not created by random assignment. Before-and-after designs have pretest and post-test but not comparison group.
