7 5: Between Subject Designs
Table Of Content Individual differences may threaten validity IV. Chapter 4: Psychological Measurement Extraneous variables (EV) Counterbalancing Related Behavioral Science Terms Matched Groups A large participant pool is necessary Using this design, participants in the various conditions are matched on the dependent variable or on some extraneous variable(s) prior the manipulation of the independent variable. This guarantees that these variables will not be confounded across the experimental conditions. For instance, if we want to determine whether expressive writing affects people’s health then we could start by measuring various health-related variables in our prospective research participants. We could then use that information to rank-order participants according to how healthy or unhealthy they are. Next, the two healthiest participants would be randomly assigned to complete different conditions (one would be randomly assigned to the traumatic experiences writing conditio...