Belief, knowledge, and uncertainty: A cognitive perspective on subjective probability

The application of Dempster-Shafer theory demonstrated with justification provided by legal evidence

In forecasting and decision making, people can and often do represent a degree of belief in some proposition. At least two separate constructs capture such degrees of belief: likelihoods capturing evidential balance and support capturing evidential weight. This paper explores the weight or justification that evidence affords propositions, with subjects communicating using a belief function in hypothetical legal situations, where justification is a relevant goal. Subjects evaluated the impact of sets of 1–3 pieces of evidence, varying in complexity, within a hypothetical legal situation. The study demonstrates the potential usefulness of this evidential weight measure as an alternative or complement to the more-studied probability measure. Subjects’ responses indicated that weight and likelihood were distinguished; that subjects’ evidential weight tended toward single elements in a targeted fashion; and, that there were identifiable individual differences in reactions to conflicting evidence. Specifically, most subjects reacted to conflicting evidence that supported disjoint sets of suspects with continued support in the implicated sets, although an identifiable minority reacted by pulling back their support, expressing indecisiveness. Such individuals would likely require a greater amount of evidence than the others to counteract this tendency in support. Thus, the study identifies the value of understanding evidential weight as distinct from likelihood, informs our understanding of the psychology of individuals’ judgments of evidential weight, and furthers the application and meaningfulness of belief functions as a communication language.

The effect of DTC advertisement content on belief tenacity: A study of appeals and argument types

BACKGROUND

Direct-to-consumer advertising (DTCA) has an influence on patients' perceptions, awareness, and behaviors. Inoculation theory and the model of belief processing provide insights into cognition that stand to increase our understanding of how patients process the information presented in these advertisements and form beliefs about medications.

OBJECTIVE

This study was conducted to evaluate the effect of sidedness of appeals and argument types in understanding beliefs that are formed after exposure to advertisements. DTCA and negative experiences were used to study these constructs.

METHODS

A 2 (1-sided vs 2-sided appeals) x 2 (causal vs authoritative arguments) factorial study design was used. A total of 263 undergraduate students were assigned to view 1 of the 4 mock flu-medication advertisements and complete a questionnaire. Subjects were then presented with a negative scenario and were asked to fill out a questionnaire based on the information in the ad and in the negative scenario. The dependent measures included belief change, change in intent to inquire, and standardized price change. Data were analyzed using 2-way analysis of variance.

RESULTS

Subjects exposed to 2-sided appeals showed lower belief change, standardized price change, and change in intent to inquire following a negative experience than subjects exposed to 1-sided appeals (P<.05). No significant difference was found between subjects who received causal arguments and those who received authoritative arguments. A significant interaction effect was observed between sidedness of appeal and argument type on initial belief and initial intent to inquire.

CONCLUSIONS

Some support for aspects of inoculation theory and theory of belief formation was found. The findings suggest that complying with the "fair-balance" requirement may be beneficial to pharmaceutical marketers as 2-sided appeals increase the tenacity of consumers' beliefs. Higher initial belief and intent to inquire when causal arguments are used in 2-sided promotional messages suggest that use of data to substantiate claims in advertisements may result in enhanced beliefs about the merits of advertised medication.

Self-management decision influences in heart failure: a preliminary investigation

Self-management decision making places significant cognitive demands on individuals with heart failure (HF). Before theoretically valid decision supports can be developed, a better understanding of underlying decision characteristics is needed. The purpose of this preliminary study was to describe sources of self-management decision influences for individuals (N = 38) with varying levels of HF (New York Heart Association (NYHA) classifications). Therapeutic value was the most influential source of self-management decision making for these patients, followed by personal beliefs and values, information sources, symptom influence, and task difficulty across all NYHA classes. Symptom influence was least influential for persons in Class II, whereas task difficulty was least influential for those in Classes III and IV. Moderate and significant associations were noted between information sources and personal beliefs and values and between information sources and symptom influence. As the disease progressed, a trend toward fewer decision influences, especially in the task difficulty scale, was noted.

Understanding how patients form beliefs about pharmacists' trustworthiness using a model of belief processing

OBJECTIVE

To determine what information people use in forming beliefs about pharmacists' trustworthiness and to determine whether these pieces of information can be categorized using elements of a model of belief processing.

DESIGN

Participants in two focus groups were asked about the trustworthiness of pharmacists in one dispensing scenario and two pharmaceutical care scenarios. Transcripts were analyzed, and each piece of information provided was coded as an evidence statement or a claim, according to a model of belief processing.

SETTING

University campus.

PARTICIPANTS

University staff and students.

MAIN OUTCOME MEASURES

Information used to form beliefs about pharmacists' trustworthiness and classification of the information using constructs from the model of belief processing.

RESULTS

Coders identified 92 evidence statements and 19 claims. An evaluation of the data across the scenarios using predetermined criteria showed 20 evidence statements and 11 claims to be the most salient pieces of information used to form beliefs about pharmacists' trustworthiness. In considering the pharmaceutical care scenarios, participants focused more on communication and interpersonal skills when forming a trustworthiness belief. The information could be categorized as evidence statements or claims, which are parts of arguments as described by a model of belief processing.

CONCLUSION

The study participants used the pharmacists' credentials, communication skills, personableness, and appearance to form trustworthiness beliefs. Overall, they wanted pharmacists to be honest, knowledgeable, and caring. Variables used to form trustworthiness beliefs represent different levels of abstraction that can be detected and coded using a model of belief processing.

Normative and Descriptive Analyses of Simpson's Paradox in Decision Making

Suppose that you are evaluating two delivery companies. Your investigation shows that Company B has a better on-time rate for small packages and also for large packages. Despite Company B's performance, however, Company A has a better overall on-time rate. This situation exemplifies Simpson's Paradox, in which the judged relationship between two variables (e.g., company and performance) differs depending on whether that relationship is viewed within subcategories of a third variable (e.g., package size) or in the aggregate. A normative analysis is presented arguing that the reasonableness of using the third variable depends upon the sample size as well as the separation between and variability within categories. To test subjects' abilities to behave appropriately in Simpson's Paradox situations, we examined responses to variations in these factors in five studies. Results showed that subjects had little or no sensitivity to differing stimulus set sizes. Also, subjects were sensitive to relationship strength and the variability within and between groups, and in nonnormative ways. Subjects' judgment behavior is related to a broader perspective concerning selection among multiple available levels of analysis based on a consideration of argument strength. Copyright 2000 Academic Press.

Judgment and Response Processes across Two Knowledge Domains

Wallsten and Gonzalez-Vallejo (1994) developed the Stochastic Judgment Model to account for true-false judgment and response processes in a single well-defined knowledge domain. This paper generalizes the model to a four-category rating task that encompasses two knowledge domains simultaneously. It then applies the model to an experiment in which Ph.D. students in history and English literature rated confidence in the truth of statements in both domains, and also decided which statement within a pair consisting of one from each domain was more likely true. Constrained versions of the general model fit the rating data very well and accurately predicted the pair-comparison (PC) choices. The results suggest that (a) the mean distance between the true and false statement distributions of confidence was greater in the better known domain; (b) judged confidence variability is greater in the domain of greater knowledge; while simultaneously (c) criterion variability is constant across domains; (d) the extreme response criteria are located symmetrically around the central one; which (e) is located to yield the usual bias to call statements true. Finally, cross-domain PC choices were very well predicted by assuming that respondents judged only the statement in the single domain they knew better and not well predicted by the more common assumption that they compare their levels of confidence in the two statements. Implications for the underlying cognitive processes are discussed including the effects of expertise. Copyright 1998 Academic Press.