Instance‐based learning in dynamic decision making

This paper presents a learning theory pertinent to dynamic decision making (DDM) called instancebased learning theory (IBLT). IBLT proposes five learning mechanisms in the context of a decision‐making process: instance‐based knowledge, recognition‐based retrieval, adaptive strategies, necessity‐based choice, and feedback updates. IBLT suggests in DDM people learn with the accumulation and refinement of instances, containing the decision‐making situation, action, and utility of decisions. As decision makers interact with a dynamic task, they recognize a situation according to its similarity to past instances, adapt their judgment strategies from heuristic‐based to instance‐based, and refine the accumulated knowledge according to feedback on the result of their actions. The IBLT's learning mechanisms have been implemented in an ACT‐R cognitive model. Through a series of experiments, this paper shows how the IBLT's learning mechanisms closely approximate the relative trend magnitude and performance of human data. Although the cognitive model is bounded within the context of a dynamic task, the IBLT is a general theory of decision making applicable to other dynamic environments.     

Differential weighting in choice versus advice: I’ll do this,you do that

We propose that when individuals make a decision for themselves they weight attributes more uniformly compared to when they give advice. In Study 1, 138 participants were given a hypothetical choice between two jobs varying on two dimensions and asked either to choose for themselves, offer advice to a best friend, or offer advice to an acquaintance. We hypothesized that respondents offering advice would favor the option with the higher value on the more important dimension. More participants in the acquaintance condition recommended the job with a higher value on the important dimension than participants making the choice for themselves. Study 2 (N=62) tested the hypothesis in a situation where the options consisted of three dimensions. One option was relatively high on two of the three dimensions and the other option was relatively high on the remaining ‘socially important’, or ‘prominent’, dimension. The uniform weighting hypothesis for self‐choice predicts higher frequency of choice for the former option. Data were consistent with this prediction. Study 3 (N=170) tested the hypothesis in students' choice of major at the university. We made use of an actual event, a pending university budget cut, that would require some students to change majors. Participants either made the decision for themselves, made a recommendation to a student in their same department, or made a recommendation to a student in another department facing the analogous dilemma. Replicating the findings of the first two studies, participants offering advice to a student in another department suggested staying with their current major significantly more than participants making the choice for themselves. Copyright © 1999 John Wiley & Sons, Ltd.     

Cleaning versus replacement in power plant air preheaters: a comparison between deterministic and stochastic goal programming models

Power plants lose efficiency when the air preheater elements are not replaced or cleaned as they deteriorate. Replacing is more expensive than cleaning but more secure to preserve power and lifetime. How many baskets should be then replaced and how many cleaned to achieve ‘satisficing’ goals of cost, power and lifetime? We design deterministic/stochastic goal programming approaches to this problem and develop a decision case for usual preheaters. Some discrepancies in results between both approaches appear, the deterministic model advising to replace less baskets than the stochastic, which is plausible due to the risk variable. Copyright © 2005 John Wiley & Sons, Ltd.     

Testosterone and attribution of successful competition

Mood, personal merit, and/or its perception have been suggested to be mediating factors in testosterone responses to competition. Previously we have found that personal contribution and attribution were related to testosterone levels after successful competition. To confirm such associations, two basketball teams (n = 17 players) that emerged as winners in two actual matches were studied. Salivary testosterone levels and mood were measured before and after the games. Individual contribution to the outcome was assessed, and personal satisfaction and causal attribution of outcome were reported by players. Testosterone concentrations increased to near significance in Team 1 but not in Team 2, who attributed their victory more to luck than did Team 1. This latter team showed notably decreased vigor, and both teams showed fatigue at the end of the match. Post‐match testosterone levels were only significantly, negatively related to external attribution. The results support the idea that causal attribution of the outcome is contributing to the variance of the testosterone responses to real confrontations where the outcome is highly dependent on personal merit. Aggr. Behav. 26:235–240, 2000. © 2000 Wiley‐Liss, Inc.     

Aggressive and socially insecure behaviors in kindergarten and elementary school students: a comparative study concerning gender,age and geographical background of children in Northern Greece

Social Psychology of Education - Aggression and social insecurity in children have received a lot of attention in recent research. In the current study the purpose was to examine whether specific...