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Decision Making in Groups : Group membership effects on post-decision processes

Eisele, Per LU (1999)
Abstract
The present thesis examines differences in post-decision processes between members of groups and individual decision makers. The empirical studies employed a decision theoretical framework based on Differentiation and Consolidation (Diff Con) Theory. Diff Con theory proposes that decision makers strive to achieve sufficient differentiation in their evaluation of one alternative versus competing alternatives to be able to make a decision and that this process of differentiation continues during the post-decision period. This post-decision differentiation is also referred to as consolidation. In each of the four studies contained in the thesis, consolidation for group members was compared with that for individual decision makers. Study I... (More)
The present thesis examines differences in post-decision processes between members of groups and individual decision makers. The empirical studies employed a decision theoretical framework based on Differentiation and Consolidation (Diff Con) Theory. Diff Con theory proposes that decision makers strive to achieve sufficient differentiation in their evaluation of one alternative versus competing alternatives to be able to make a decision and that this process of differentiation continues during the post-decision period. This post-decision differentiation is also referred to as consolidation. In each of the four studies contained in the thesis, consolidation for group members was compared with that for individual decision makers. Study I involved two experiments. In Experiment 1 there were two group discussion conditions, being instructed to reach consensus before deciding and being instructed that a majority-vote would be sufficient to make a group decision. In Experiment 2, group decision making with face-to-face interaction was compared with that involving information exchange only. The results of both Experiment 1 and Experiment 2 indicated that, whereas individual decision makers consolidated their decisions, group members did not consolidate the decisions made by their groups. No differences in consolidation were found between the different group decision-making conditions.



In Study II, group members were classified on the basis of Bales´ SYMLOG instrument as being task-oriented or socially oriented in making their decisions. Whereas task-oriented group members were found to consolidate their decisions, socially oriented group members were not.



In Study III, consolidation in individual decision makers and in interactive decision makers (interacting in dyads or in triads an then making a persoanl decision) were compared. The decision makers were classified according to whether their preferred decision strategy as reported by them was a compensatory (considering all attributes) or a non-compensatory one (focusing only on the most important attributes). Only participants using a non-compensatory decision strategy were found to consolidate their decisions.



In Study IV, decision-making group members were found to consolidate the group decisions less than individual decision makers, and participants using a non-compensatory decision strategy to consolidate their decisions more than participants using a compensatory decision strategy, both results replicating earlier results. In addition, the disagreement information hypothesis, namely that disagreement (or decision-threatening) information increases post-decision consolidation, was tested. It was also argued that group members would be less susceptible to disagreement information than individual decision makers, due to their focusing on information shared by the group members, at the cost of the unshared information. Results indicated that disagreement information given to participants (both group members and individual decision-makers) after they have made a decision further enhance post-decision consolidation. (Less)
Abstract (Swedish)
Popular Abstract in Swedish

Doktorsavhandlingen handlar om beslutsfattande i grupp och innehåller studier om efterbeslutsprocesser. Gruppmedlemmar i olika experimentellt skapade sociala situationer jämförs med individuella beslutsfattare. Metoden är alltså i huvudsak experimentell, men en kvalitativ metod har också använts för att studera kommunikationen under gruppdiskussionerna.



Studierna använder ett beslutsteoretiskt ramverk byggt på Differentierings- och konsolideringsteorin, skapad av Ola Svenson vid Stockholms universitet. Denna teori antar att människor måste särskilja alternativ tillräckligt mycket för att kunna göra ett val. Det räcker inte med att ett alternativ är bättre än andra alternativ,... (More)
Popular Abstract in Swedish

Doktorsavhandlingen handlar om beslutsfattande i grupp och innehåller studier om efterbeslutsprocesser. Gruppmedlemmar i olika experimentellt skapade sociala situationer jämförs med individuella beslutsfattare. Metoden är alltså i huvudsak experimentell, men en kvalitativ metod har också använts för att studera kommunikationen under gruppdiskussionerna.



Studierna använder ett beslutsteoretiskt ramverk byggt på Differentierings- och konsolideringsteorin, skapad av Ola Svenson vid Stockholms universitet. Denna teori antar att människor måste särskilja alternativ tillräckligt mycket för att kunna göra ett val. Det räcker inte med att ett alternativ är bättre än andra alternativ, det måste vara så mycket bättre att beslutsfattaren kan försvara sitt beslut mot framtida hot, som till exempel ny information, kritik av andra personer eller känsla av ånger.



Studie I innehöll två experiment. Gruppsituationen i det första experimentet bestod av grupper som dels var instruerade att de måste fatta ett konsensus beslut dels av grupper som var instruerade att majoritetsröstning är okay. I det andra experimentet undersöktes skillnader mellan direkt interaktion (öga-mot-öga) och indirekt interaktion (informationsutbyte). Studie II bestod av en SYMLOG (en metod för klassificering av social interaktionstil) analys av videoinspelade grupper. Medlemmar klassificerades bland annat som uppgiftsorienterade kontra socialt orienterade. I studie III jämfördes interaktiva beslut med individuella beslut. Interaktiva beslut är personliga beslut fattade efter en gruppdiskussion. I denna och nästföljande studie klassificerades också försökspersonerna utifrån vilken beslutstrategi de använt. En icke-kompensatorisk beslutstrategi beskrivs här som fokusering på en eller två viktiga beslutsrelaterade egenskaper medan en kompensatorisk beslutstrategi innefattar summering av eller jämförelse mellan alla eller många egenskaper. I studie IV testades en förklaring av huvudresultatet, att gruppmedlemmar konsoliderar gruppernas beslut mindre än individuella beslutsfattare. Förklaringen går ut på att mothuggs- (eller beslutshotande) information ökar tendensen till beslutskonsolidering. Under gruppdiskussionerna tonas denna typ av information ner till förmån för medhålls- (eller beslutstödjande) information. Resultat visar på att 1) användandet av en icke-kompensatorisk beslutstrategi ökar tendensen att konsolidera beslut. 2) mottagande av mothuggsinformation ökar också denna tendens. Skillnaderna mellan gruppmedlemmar och individuella beslutsfattare var dock ej statistiskt signifikanta gällande just dessa två ämnen. (Less)
Please use this url to cite or link to this publication:
author
supervisor
opponent
  • Professor Verplanken, Bas
organization
publishing date
type
Thesis
publication status
published
subject
keywords
group membership., social interaction style, group decision-making, decision strategy, Decision, post-decision processes, Psychology, Psykologi
pages
173 pages
publisher
Department of Psychology, Lund University
defense location
Kulturens Auditorium
defense date
1999-09-17 10:00:00
external identifiers
  • other:ISRN: LUSADG/SAPS--99/1082--SE
ISBN
91-628-3658-7
language
English
LU publication?
yes
id
e8fe5c52-9590-4d98-87cc-78ce86da1db8 (old id 39784)
date added to LUP
2016-04-04 12:14:37
date last changed
2021-11-24 16:47:49
@phdthesis{e8fe5c52-9590-4d98-87cc-78ce86da1db8,
  abstract     = {{The present thesis examines differences in post-decision processes between members of groups and individual decision makers. The empirical studies employed a decision theoretical framework based on Differentiation and Consolidation (Diff Con) Theory. Diff Con theory proposes that decision makers strive to achieve sufficient differentiation in their evaluation of one alternative versus competing alternatives to be able to make a decision and that this process of differentiation continues during the post-decision period. This post-decision differentiation is also referred to as consolidation. In each of the four studies contained in the thesis, consolidation for group members was compared with that for individual decision makers. Study I involved two experiments. In Experiment 1 there were two group discussion conditions, being instructed to reach consensus before deciding and being instructed that a majority-vote would be sufficient to make a group decision. In Experiment 2, group decision making with face-to-face interaction was compared with that involving information exchange only. The results of both Experiment 1 and Experiment 2 indicated that, whereas individual decision makers consolidated their decisions, group members did not consolidate the decisions made by their groups. No differences in consolidation were found between the different group decision-making conditions.<br/><br>
<br/><br>
In Study II, group members were classified on the basis of Bales´ SYMLOG instrument as being task-oriented or socially oriented in making their decisions. Whereas task-oriented group members were found to consolidate their decisions, socially oriented group members were not.<br/><br>
<br/><br>
In Study III, consolidation in individual decision makers and in interactive decision makers (interacting in dyads or in triads an then making a persoanl decision) were compared. The decision makers were classified according to whether their preferred decision strategy as reported by them was a compensatory (considering all attributes) or a non-compensatory one (focusing only on the most important attributes). Only participants using a non-compensatory decision strategy were found to consolidate their decisions.<br/><br>
<br/><br>
In Study IV, decision-making group members were found to consolidate the group decisions less than individual decision makers, and participants using a non-compensatory decision strategy to consolidate their decisions more than participants using a compensatory decision strategy, both results replicating earlier results. In addition, the disagreement information hypothesis, namely that disagreement (or decision-threatening) information increases post-decision consolidation, was tested. It was also argued that group members would be less susceptible to disagreement information than individual decision makers, due to their focusing on information shared by the group members, at the cost of the unshared information. Results indicated that disagreement information given to participants (both group members and individual decision-makers) after they have made a decision further enhance post-decision consolidation.}},
  author       = {{Eisele, Per}},
  isbn         = {{91-628-3658-7}},
  keywords     = {{group membership.; social interaction style; group decision-making; decision strategy; Decision; post-decision processes; Psychology; Psykologi}},
  language     = {{eng}},
  publisher    = {{Department of Psychology, Lund University}},
  school       = {{Lund University}},
  title        = {{Decision Making in Groups : Group membership effects on post-decision processes}},
  year         = {{1999}},
}