Suchergebnisse

Nach Tversky und Kahnemans (1973) 'availability (Erreichbarkeit) heuristic' schätzen Individuen die Häufigkeit oder die Wahrscheinlichkeit eines Ereignisses danach ein, mit welcher Leichtigkeit ihnen Beispiele oder Assoziationen einfallen. Der vorliegend Beitrag zeigt, daß in den Forschungen zu diesem Ansatz die Leichtigkeit, mit der sich an etwas erinnert wird, und der Umfang des Erinnerten nicht unterschieden werden. Anhand eines Experiments mit den Einschätzungsurteilen von 28 Studenten wird der Ansatz einer methodischen und analytischen Revision unterzogen. (pmb)

Es wird von drei Experimenten berichtet, die zeigen, daß Individuen subjektiv erlebtes Erinnerungsvermögen als Information bei der Bewertung der Bedeutung des Erinnerten benutzen. Besonders diejenigen Testpersonen, die sich an Situationen erinnern sollten, in denen sie sich positiv verhielten und sich wohlfühlten, schätzten sich im Rückblick positiver ein als Personen, die sich Situationen ins Gedächtnis rufen sollten, in denen sie sich nicht positiv verhielten und sich unsicher fühlten. Dieser Effekt der Wertigkeit der Erinnerung bestand jedoch nur bei denjenigen Testpersonen, die sich an sechs Beispiele der betreffenden Wertigkeit erinnern sollten, was ihnen leichtfiel. Wenn sich die Personen an zwölf Beispiele erinnern sollten, was sie schwierig fanden, kehrte sich die Wirkung der Wertigkeit ins Gegenteil um. In diesem Fall berichteten die Testpersonen eher von einem positiven Gefühl bei der Erinnerung an Beispiele negativen als an Beispiele positiven Verhaltens. Offensichtlich kamen sie zu dem Schluß, daß die Verhaltensweisen, an die sie sich erinnerten, nicht häufig oder typisch sein konnten, wenn sie nur schwierig ins Gedächtnis zu rufen waren (Experimente 1 und 2). In Übereinstimmung mit dieser Interpretation wurde die Wirkung des erlebten Erinnerungsvermögens ausgeschaltet, wenn die Testpersonen ihre subjektiven Erfahrungen irrigerweise auf die Wirkung vorübergehender äußerer Einflüsse zurückführen konnten (Experiment 3). Diskutiert werden die Konsequenzen für das Wirken besonders der Verfügbarkeitsheuristik und der Funktionen subjektiver Erfahrungen als Information im allgemeinen. (ICAübers)

ABSTRACTThis paper presents a tractable set of integer programming models for the days‐off scheduling of a mix of full‐ and part‐time employees working α to β days/week (cycle) in a multiple‐objective, multiple‐location environment. Previous models were formulated to specifically schedule part‐time employees working either two or three days per week. These models were intractable because they required complete employee schedule information. The new models are deemed implicit optimal since they are required to supply only essential information. While the number of variables in previous models is an exponential increasing function of β‐α, the size of three of the new models is independent of α and β.The first three models developed here (as in [18]) deal with the trade‐offs between idle time, the number of employees required to work at multiple "locations," and the size of the total labor pool. The inherent flexibility of the implicit modeling approach is illustrated by the presentation of various modifications of the basic models. These modifications permit the use of preference weights on the number of employee work days/week (cycle) or the minimization of payroll costs where differential pay rates exist. These latter models may also be formulated such that idle time is ignored, constrained or minimized.The execution time for the implicit models (on a CDC CYBER 730 computer with commercially available software) averaged well under five seconds on 1200 trial problems for the type of application considered in [18]. A solution was obtained in less than 46 seconds of CPU time for a trial problem which would have required over 1.4 million integer variables with previous models.The availability of optimal solutions was invaluable in the development of two heuristics designed to deal with the trade‐offs of [16]. In an experimental analysis a previous heuristic produced results which averaged from 74 to 508 percent above optimum across six experimental conditions. The comparable new heuristic produced results which averaged from 3 to 8 percent above optimum for the same experimental conditions.The paper concludes by developing a framework to integrate the results of this research with the tour scheduling problem and by identifying several other areas for related research.

ABSTRACTThe dual problem of work tour scheduling and task assignment involving workers who differ in their times of availability and task qualifications is examined in this paper. The problem is presented in the context of a fast food restaurant, but applies equally well to a diverse set of service operations. Developing a week‐long labor schedule is a nontrivial problem, in terms of complexity and importance, which a manager spends as much as a full workday solving.The primary scheduling objective (the manager's concern) is the minimization of overstaffing in the face of significant hourly and daily fluctuations in minimum staffing requirements. The secondary objective (the workers' concern) is the minimization of the sum of the squared differences between the number of work hours scheduled and the number targeted for each employee. Contributing to scheduling complexity are constraints on the structure of work tours, including minimum and maximum shift lengths and a maximum number of workdays.A goal programming formulation of a representative problem is shown to be too large, for all practical purposes, to be solved optimally. Existing heuristic procedures related to this research possess inherent limitations which render them inadequate for our purposes. Subsequently, we propose and demonstrate a computerized heuristic procedure capable of producing a labor schedule requiring at most minor refinement by a manager.

In the present study it was shown that both decision heuristics and social value orientation play important roles in the building of preferences. This was revealed in decision tasks in which participants were deciding about candidates for a job position. An eye-tracking equipment was applied in order to register participants' information acquisition. It was revealed that participants performing well on a series of heuristics tasks (availability, representativeness, anchoríng & adjustment, and attribution) including a confidence judgment also behaved more accurately than low performers in the fulfillment of the preference tasks. It was also established that the high performers were not as influenced by whether uncertainty was presented in terms of probabilities or in terms of frequencies as was the low performers. With regard to social value orientation the results revealed that decision processing differences were more systematic between cooperators and competitors than between cooperators and individualists. Also, the cooperators did not seem to attend more to proenvironmental goals than to profit goals in the evaluation of the candidates. Finally, it was shown that accountable cooperators invested more time in their decisions than those that were not accountable, and that no such difference was observed between accountable and not accountable competitors or individualists.

Social workers are constantly seeking useful data regarding methods of behavior change. Changes in self-concept can mediate changes in overt behavior. Self-concept has been reawakened as a focus of empirical research. Several literatures (self-perception theory, cognitive dissonance theory, and the availability heuristic literature) suggest ways of changing the self-concept. This article reviews existing literature and discusses the guidelines for changing self-concept that derive from empirical research in the previously mentioned literatures. The manner in which these guidelines explain the success of particular intervention techniques is delineated. Suggestions for new social work practice interventions are proffered, as are examples from the authors'practice experience.

This study conceptualizes the cultivation effect in terms of the accessibility of information in memory. Contemporary social cognition research indicates that individuals consistenly use the most accessible information in memory as a basis for a variety of judgments. Consistent with this body of literature, the current study demonstrates that, based on a reaction time task, those subjects who watch comparatively more television not only overestimate frequency or probability but also give faster responses to various types of cultivation questions. These results support the notion that relevant information, presumably "cultivated" from television viewing, is more accessible in memory for heavier viewers, and, consistent with predictions made by the availability heuristic literature, overestimations of frequency or probability are associated with this enhanced accessibility. Moreover, when controlling for speed of response in the correlation between television viewing and social reality estimates, the relationship is diminished or disappears entirely, suggesting that enhanced accessibility of relevant information for heavier viewers can at least partially account for the cultivation effect.

Reeder (Reeder, 1985; Reeder & Brewer, 1979) posited a schematic model of dispositional attributions to explain negativity effects in social cognition. However, in Reeder's schematic model of dispositional attributions, it is assumed that social perceivers' processing objective is to form an impression of a social actor. Based on Reeder and Brewer's hierarchical schema, it was predicted that mock jurors processing testimony under impression-set conditions would rate a witness to be more deceptive if the witness testified truthfully before lying than when the witness was caught lying first before telling the truth. Under memory-set conditions, based on the availability heuristic, mock jurors were predicted to rate the witness to be more deceptive when the witness lied first before telling the truth compared to when the witness told the truth first before lying. To test the hypothesis, subjects played the roles of mock jurors and watched a videotape of a witness presenting testimony during a trial. The witness was caught perjuring him- or herself by the attorney either on the first response to the attorney's queries or on the fourth response. Results confirmed the hypothesis. When subjects processed the attorney-witness interaction under impression-set objectives, subjects formed stronger judgments of the witness's deceptiveness when he or she lied on the first answer; the pattern was reversed under memory-set conditions.

Despite relatively low crime rates, the Irish public believes itself to be experiencing a law and order crisis. In this article, it is argued that a plausible explanation for the public misperception is the distorted image of crime in the media. A sample of over 2000 Irish newspaper articles dealing with crime is analysed and it is argued that there are four ways in which the press skews the representation of crime. These are the bias towards extreme and atypical offences in terms of frequency, the bias towards those extreme offences in terms of newspaper space, the bias towards stories involving vulnerable victims and invulnerable offenders and the bias towards pessimistic accounts of the criminal justice system generally. By incorporating the cognitive heuristic of `availability', an elegant explanation of the relationship between biased media accounts and distorted public opinion can be offered.

We consider modeling and operational analysis of a generic asymmetric service-system situation in which (a) Red agents, potentially threatening, but possibly requiring assistance, arrive according to some partially known and possibly changing pattern in time and space; and (b) Reds are impatient: have effectively limited unknown deadlines or times of availability for Blue service, i.e., detection, classification, and attack in a military setting, or emergency assistance in other settings, such as medical care. We discuss various service options by Blue service agents and devise several approximations allowing one to compute efficiently proportions of tasks of different types that are successfully served or, more generally, if different rewards are associated with different types of tasks, the percentage of the possible reward gained. We suggest a heuristic policy for a Blue server to select the next task to perform and to decide how much time to allocate to that service. We discuss this and related policies for a number of specific examples.

Wireless communication is used in many different situations such as mobile telephony, radio and TV broadcasting, satellite communication, and military operations. In each of these situations a frequency assignment problem arises with application specific characteristics. Researchers have developed different modeling ideas for each of the features of the problem, such as the handling of interference among radio signals, the availability of frequencies, and the optimization criterion. This survey gives an overview of the models and methods that the literature provides on the topic. We present a broad description of the practical settings in which frequency assignment is applied. We also present a classification of the different models and formulations described in the literature, such that the common features of the models are emphasized. The solution methods are divided in two parts. Optimization and lower bounding techniques on the one hand, and heuristic search techniques on the other hand. The literature is classified according to the used methods. Again, we emphasize the common features, used in the different papers. The quality of the solution methods is compared, whenever possible, on publicly available benchmark instances.

Wireless communication is used in many different situations such as mobile telephony, radio and TV broadcasting, satellite communication, and military operations. In each of these situations a frequency assignment problem arises with application specific characteristics. Researchers have developed different modeling ideas for each of the features of the problem, such as the handling of interference among radio signals, the availability of frequencies, and the optimization criterion. This survey gives an overview of the models and methods that the literature provides on the topic. We present a broad description of the practical settings in which frequency assignment is applied. We also present a classification of the different models and formulations described in the literature, such that the common features of the models are emphasized. The solution methods are divided in two parts. Optimization and lower bounding techniques on the one hand, and heuristic search techniques on the other hand. The literature is classified according to the used methods. Again, we emphasize the common features, used in the different papers. The quality of the solution methods is compared, whenever possible, on publicly available benchmark instances.

{\begin{rawhtml} Revised Version unter http://dx.doi.org/10.1007/s10479-007-0178-0 \end{rawhtml}} Wireless communication is used in many different situations such as mobile telephony, radio and TV broadcasting, satellite communication, and military operations. In each of these situations a frequency assignment problem arises with application specific characteristics. Researchers have developed different modelling ideas for each of the features of the problem, such as the handling of interference among radio signals, the availability of frequencies, and the optimization criterion. This survey gives an overview of the models and methods that the literature provides on the topic. We present a broad description of the practical settings in which frequency assignment is applied. We also present a classification of the different models and formulations described in the literature, such that the common features of the models are emphasized. The solution methods are divided in two parts. Optimization and lower bounding techniques on the one hand, and heuristic search techniques on the other hand. The literature is classified according to the used methods. Again, we emphasize the common features, used in the different papers. The quality of the solution methods is compared, whenever possible, on publicly available benchmark instances.