| Abstrakt: |
Two methodological issues involving the Velten (1968) mood induction technique are examined. The first issue concerns threats to statistical conclusion validity that result from the use of some group mood induction techniques: In research on the effects of mood, groups of subjects are often assigned to mood conditions, whereas individuals are treated as the unit of analysis. It is argued that this procedure threatens the validity of inferences about mood effects, in particular by inflating Type I error.The use of a group mood induction, with only one mood manipulated in a particular group, also increases the likelihood of experimenter bias, local history effects, or both. This article illustrates an alternative method of group mood induction involving four modifications to the Velten (1968) mood induction procedure. Using this revised procedure, subjects are randomly assigned to different mood conditions, yet the data are collected simultaneously. Results indicate that this method is successful in inducing moods. This technique avoids the problem associated with assigning groups to conditions, but retains the economy of group sessions. The second issue concerns the temporal duration of the Velten procedure. We demonstrate that our modified procedure, with the inclusion of an incubation period, leads to mood change lasting up to 35 min. Further, our modified Velten procedure resulted in mood differences, even after various intervening tasks. The technique was discussed in terms of demand characteristics, experimenter bias, local history, and ethics. [ABSTRACT FROM AUTHOR] |
