SCALING VELOCITY AND SPACE FROM TIME ESTIMATES

A model described by the relation, relative estimated time = (subjective space)/(subjective velocity), is applied on time estimates collected in three experiments with moving spots indicating the time intervals which were estimated. The model is found to account satisfactorily for the data, thus permitting derivations of subjective scales of velocity and space.     

Postdecision consolidation in a trend prediction task

To be able to learn from experience it is necessary to correctly apprehend experienced feedback and the situation in which it is provided. The results indicate how post-decision consolidation in complex domains may affect learning. The problem may be particularly pertinent in recurrent decision making where considerable risk is involved. The study explores the changes in aspect (signal) importance from pre- to postdiction as a function of outcome information. By postdiction we mean the remembering of an earlier prediction (cf. Hawkins & Hastie, 1990). Subjects were asked to decide on which of four alternative future price developments would follow a historical price trajectory for different commodities, and to rate the importance of each of the chosen alternative's corresponding aspects. The subjects revealed a bias in their support ratings of aspects--seeing support in aspects that traditionally (by themselves and in many contexts) would be seen as neutral or even counter-indicative of the alternative chosen. After an intermission, the subjects were also given information about what was indicated to be the actual development of the market. One group was told that their decisions were correct (irrespective of what the decisions were), another group that they were incorrect but close, a third group that they were incorrect by far, while a fourth group served as a control. Following this information the subjects were again asked to judge the importance of the aspects for their own prior decision on the most likely future development. The results indicated that outcome feed-back had an effect on post decision restructuring of facts. Subjects in the correct condition showed an average consolidation that increased the support, while the wrong conditions lead to negative consolidation (in retrospect indicating that they never found as much support for their decision in the past as they actually did). Thus, in a choice between consolidating their own initial prediction and the price trajectory they would have to live with, the decision makers consolidated the outcome. Therefore, the results of the study were related to the hindsight bias phenomenon (Fischhoff, 1975) and to Kahneman and Miller's (1986) mutability concept.     

Individual postdecision processes in group settings

In two experiments Differentiation and Consolidation Theory (Diff Con) (Svenson, 1992) was used to investigate individual postdecision making processes in three-member groups. It was predicted that in groups in which the subjects preferred different alternatives (conflict groups), subjects would consolidate their own preferred alternative, and not the group's final decision. A second hypothesis was that no consolidation would be indicated in groups in which all members preferred the same alternative (non-conflict groups). The results showed that in conflict groups, the members who gave up their preferred alternative (minority members) consolidated their own preference, thereby significantly regretting the group decision. In contrast, members who got their own will through in the majority decision (majority members) showed no consolidation of the group decision. The corresponding pattern of results was replicated in a second experiment, using a different decision situation. The results indicated that perceptions of social support, agreement in a group and decreasing responsibility for a group's decision, could all partly substitute consolidation by attractiveness restructuring.     

Adolescent smoking behavior and outcome expectancies

Adolescent smoking behavior is assumed to be associated with smoking outcome expectancies. Results in this paper are based on data from the control group of two data collections among Norwegian secondary school students taken approximately 30 months apart (T1 and T2). The dimensionality of smoking outcome expectancies was the same at both time points, revealing three components ("Addicted", "Not harmful" and "Social"). After correction for attenuation, the Pearson's correlation between T1 and T2 was 0.41 for the total sumscore, indicating low to moderate relative stability. When examining smoking expectancy sumscore means by smoking habits at T1 and T2, never smokers were different from smokers on both occasions. Never smokers scored low on "Social" and "Not harmful", and high on "Addictive". All associations were statistically significant (p < 0.001). The "Social" dimension was the strongest predictor of smoking behavior at T1 and T2. One of the outcome expectancy sumscores ("Addictive") at T1 predicted smoking habits at T2 after controlling for smoking habits at T1 (p < 0.01). This predictor was significant also after entering outcome expectancy sumscores at T2 into the model (p < 0.05). These results indicate that outcome expectations other than the health-related ones should be paid attention to when planning new prevention programs.