In this thesis, some old decision strategies are investigated and a new one that furthers our understanding of how decisions are made is introduced. Three studies are presented. In Study I and II, strategies are investigated in terms of inferences and in Study III, strategies are investigated in terms of preferences. Inferences refer to decisions regarding facts, e.g., whether a patient has a heart disease or not. Preferences refer to decision makers’ personal preferences between different choice alternatives, e.g., which flat out of many to choose. In all three studies, both non-compensatory strategies and compensatory strategies were investigated. In compensatory strategies, a high value in one attribute cannot compensate for a low value in another, while in non-compensatory strategies such compensation is possible. Results from Study I showed that both compensatory (logistic regression) and non-compensatory (fast and frugal) strategies make inferences equally well, but logistic regression strategies are more frugal (i.e., use fewer cues) than the fast and frugal strategies. Study II showed that the results were independent of the degree of expertise. The good inferential ability of both non-compensatory and compensatory strategies suggests there might be room for a strategy that can combine the strengths of the two. Study III introduces such a strategy, the Concordant-ranks (CR) strategy. Results from Study III showed that choices and attractiveness evaluations followed this new strategy. This strategy dictates a choice of an alternative with concordant ranks between attribute values and attribute weights when alternatives are about equally attractive. CR also serves as a proxy for finding the alternative with the shortest distance to an ideal. The CR strategy combines the computational simplicity of non-compensatory strategies with the superior information integration ability of compensatory strategies. / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: Submitted. Paper 2: Submitted.

A decision process can be conceptually separated into a perceptual process and a decision strategy. The former includes all the different mechanisms that contribute to accumulate information relevant to the decision, whereas the decision strategy determines when enough information has been accumulated and a decision can be taken. Although perceptual processes have been extensively investigated in the last decades, decision strategies have received comparatively little attention. The main aim of this work is to fill this gap by analysing four decision strategies with two different experimental paradigms. We also focus on ancillary decision-making topics, such as the effect of stimulus intensity, foreperiod duration, payoff manipulation, and the response distributions in the rate domain. We initially performed a qualitative analysis of decision strategies by using a classic reaction time tasks on human participants while assuming the Drift Diffusion Model, one of the many models used for simple and fast decisions, as the perceptual process. We found that increasing the time of the trial does not have a relevant effect on the response, which is in contrast with some of the decision rules considered here. However, this approach is limited by the implicit assumption of a perceptual model that would result in different prediction for the decision strategies. We suggest the use of a different experimental design, called the EXACT Paradigm, which allows us to analyse decision strategies without having to assume any perceptual process. We tested the feasibility of such approach and applied it to several experimental studies, including a direct comparison with a classic reaction time task. Overall, two of the four decision strategies (modified Reward Rate and Reward/Accuracy) appeared to model the data satisfactorily. We discuss several ways in which the EXACT Paradigm can be used for expanding our knowledge in the field of decision-making.

abstract: People commonly make decisions and choices that could be delayed until a later time. This investigation examines two factors that may be especially important in these types of decisions: resource stability and comparison target. I propose that these two factors interact to affect whether individuals tend to adopt a delay strategy or whether they engage in more present-oriented strategy. Specifically, this thesis study tested whether picturing one’s ideal led to the adoption of a delay strategy to a greater extent when resources were stable and to a lesser extent when resources were unstable. Participants read a house-hunting scenario in which the market was stable or unstable, and either pictured their ideal house at the beginning of the task or did not. As expected, participants in the stable housing market were more willing to delay choosing a house, though the predicted interaction between resource stability and comparison target did not emerge. Contrary to the predictions, however, participants who pictured their ideal house were more willing to choose a house immediately and were more satisfied with the house they chose. Overall, these findings did not lend support to the main argument of this investigation that picturing one’s ideal would promote a delay strategy under stable resource conditions. The finding that participants preferred immediate choice after picturing their ideal may have interesting implications for persuasion and advertising. / Dissertation/Thesis / Masters Thesis Psychology 2015

By conducting this theory-based empirical study, gathering data from working negotiators in the US and Canada, I have determined what primary dynamic activities, communication skills, and negotiation tools are used by hostage/crisis negotiators. Negotiators implement their negotiation and decision strategies differently depending on whether the situations they deal with are instrumental or expressive. I have determined which elements of negotiations and factors affecting negotiations differ while handling instrumental and expressive hostage situations. I found that the collected data did not reveal any significant relationship between handling instrumental/expressive hostage situations differently and belief in the elements of Brenda Dervin's and Shannon-Weaver's theories. I have also determined that the belief in the elements of the Dervin's and Shannon-Weaver's theories is workable and practical for negotiators to use. Based on the above findings, the model suggested by this research adds the elements and directives of Dervin's and Shannon-Weaver's models to the common approach used by the negotiators. This revised model suggests that the negotiators pay attention to the dynamics of the interactions presented between the two parties: the negotiators themselves and hostage takers. The revised model also recommends that the negotiators focus on not only the hostage takers behavioral characteristics, psychological conditions, and criminal history but also on the meaning of the sent message and the interaction itself as performed between the two parties. This perspective enables the negotiators to look at the negotiation process as information and communication process. We are not ignoring the fact that hostage negotiation is a format of extreme information management. By looking at such an extreme case, we can add to our understanding of Dervin's and Shannon-Weaver's perspectives in order to see the hostage negotiation process from a wider perspective. The revised model is not an alternative approach to the common approach most negotiators use. Instead, the revised model uses the perspective and directives of the common approach and extends its meaning and content by also focusing on Dervin's sense making theory and Shannon-Weaver's communication model perspectives. The use of the perspective of this revised model is one more tool for the negotiators to use in order to promote new ways of looking at hostage negotiation resolutions.