Verbal Probability Expressions Research Articles

People prefer to predict middle, most likely quantitative outcomes (not extreme ones), but they still over-estimate their likelihood.

Past work showed a tendency to associate verbal probabilities (e.g., possible, unlikely) with extreme quantitative outcomes, and to over-estimate the outcomes' probability of occurrence. In the first four experiments (Experiment 1, Experiments 2a-c), we tested whether this "extremity effect" reflects a general preference for extreme (vs central or less extreme) values of a distribution. Participants made predictions based on a frequency distribution in two scenarios. We did not find a preference for extreme outcomes. Instead, most of the participants made a prediction about the middle, most frequent outcome of the distribution (i.e., the modal outcome), but still over-estimated the outcomes' probabilities. In Experiment 3, we tested whether the over-estimation could be better explained by an "at least"/"at most" reading of the predictions. We found that only a minority of participants interpreted predictions as the lower/upper bounds of an open interval and that these interpretations were not associated with heightened probability estimates. In the final three experiments (Experiments 4a-c), we tested whether participants perceived extreme outcome predictions as more correct, useful and interesting than modal outcome predictions. We found that extreme and modal predictions were considered equally correct, but modal predictions were judged most useful, whereas extreme predictions were judged to be more interesting. Overall, our results indicate that the preference for extreme outcomes is limited to specific verbal probability expressions, whereas the over-estimation of the probability of quantitative outcomes may be more general than anticipated and applies to non-extreme values as well.

Dimensions of uncertainty communication: What is conveyed by verbal terms and numeric ranges

The paper reviews two strands of research on communication of uncertainty that usually have been investigated separately: (1) Probabilities attached to specific outcomes, and (2) Range judgments. Probabilities are sometimes expressed by verbal phrases (“rain is likely”) and at other times in a numeric format (“70% chance of rain”), whereas range judgments describe the potential amounts expected (“1–4 mm of rain”). Examination of previous research shows that both descriptions convey, in addition to the strength of expectations, pragmatic information about the communicative situation. For instance, so-called verbal probability expressions (VPE), as likely, unlikely, a chance, or not certain give some, albeit vague, probabilistic information, but carry in addition an implicit message about the sources of uncertainty, the outcome’s valence and severity, along with information about the speakers’ attitudes and their communicative intentions. VPEs are directional by drawing attention either to an outcome’s occurrence (“it is possible”) or to its non-occurrence (“it is doubtful”). In this sense they may be more informative than numbers. Uncertainties about outcomes in a distribution (continuous quantities) are alternatively expressed as interval estimates. The width of such intervals can function as a cue to credibility and expertise. Incomplete, one-sided intervals, where only one boundary is stated, imply directionality. “More than 100 people” suggests a crowd, while “less than 200” implies a shortfall. As with VPEs, directionally positive intervals are more frequent, and perhaps more neutral than negative ones. To convey expectancies and uncertainty in a balanced way, communicators may have to alternate between complementary frames.

An appropriate verbal probability lexicon for communicating surgical risks is unlikely to exist.

Effective risk communication about medical procedures is critical to ethical shared decision-making. Here, we explore the potential for development of an evidence-based lexicon for verbal communication of surgical risk. We found that Ear, Nose and Throat (ENT) surgeons expressed a preference for communicating such risks using verbal probability expressions (VPEs; e.g., "high risk"). However, there was considerable heterogeneity in the expressions they reported using (Study 1). Study 2 compared ENT surgeons' and laypeople's (i.e., potential patients) interpretations of the ten most frequent VPEs listed in Study 1. While both groups displayed considerable variability in interpretations, lay participants demonstrated more, as well as providing systematically higher interpretations than those of surgeons. Study 3 found that lay participants were typically unable to provide unique VPEs to differentiate between the ranges of (low) probabilities required. Taken together, these results add to arguments that reliance on VPEs for surgical risk communication is ill-advised. Not only are there systematic interpretational differences between surgeons and potential patients, but the coarse granularity of VPEs raises severe challenges for developing an appropriate evidence-based lexicon for surgical risk communication. We caution against the use of VPEs in any risk context characterized by low, but very different, probabilities. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Combining verbal forecasts: The role of directionality and the reinforcement effect

AbstractRecent research has shown that when people combine verbal probabilistic forecasts from two sources, they are not simply averaged but can reinforce each other; so when two advisors both said an event was “rather likely,” some listeners concluded that the event was “quite likely”. Conversely, when both said the event was “rather unlikely,” people concluded that it was “quite unlikely.” The present studies demonstrate that the direction of this effect is not evoked by high versus low probabilities, but by the directionality of verbal probability expressions. Some phrases are affirmative, directed towards occurrences (“there is a chance”), whereas others are negations, pointing to the possibility that the event might not occur (“it is not certain”). Two positive phrases are perceived to reinforce each other, even when they convey low probabilities, resulting in a higher combined probability estimate, whereas two negative phrases do the opposite, regardless of the probabilities they convey. We show that this effect occurs both for equal and unequal verbal phrases, regardless of the probability equivalents of the expressions. We also found a positive, but weaker, reinforcement effect of numerical probabilities.

The Interpretation of Verbal Probabilities: A Systematic Literature Review and Meta-Analysis.

Verbal probabilities such as "likely" or "probable" are commonly used to describe situations of uncertainty or risk and are easy and natural to most people. Numerous studies are devoted to the translation of verbal probability expressions to numerical probabilities. The present work aims to summarize existing research on the numerical interpretation of verbal probabilities. This was accomplished by means of a systematic literature review and meta-analysis conducted alongside the MOOSE-guidelines for meta-analysis of observational studies in epidemiology. Studies were included, if they provided empirical assignments of verbal probabilities to numerical values. The literature search identified 181 publications and finally led to 21 included articles and the procession of 35 verbal probability expressions. Sample size of the studies ranged from 11 to 683 participants and covered a period of half a century from 1967 to 2018. In half of the studies, verbal probabilities were delivered in a neutral context followed by a medical context. Mean values of the verbal probabilities range from 7.24% for the term "impossible" up to 94.79% for the term "definite". According to the results, there is a common 'across-study' consensus of 35 probability expressions for describing different degrees of probability, whose numerical interpretation follows a linear course. However, heterogeneity of studies was considerably high and should be considered as a limiting factor.

Variability in the interpretation of probability phrases used in Dutch news articles — a risk for miscommunication

Verbal probability phrases are often used in science communication to express estimated risks in words instead of numbers. In this study we look at how laypeople and statisticians interpret Dutch probability phrases that are regularly used in news articles. We found that there is a large variability in interpretations, even if the phrases are given in a neutral context. Also, statisticians do not agree on the interpretation of the phrases. We conclude that science communicators should be careful in using verbal probability expressions.

The numerical translation of verbal probability expressions by patients and clinicians in the context of peri-operative risk communication.

Shared decision-making is central to the pre-operative consent process and accurate communication of risk is dependent on a clear understanding of numerical information by both the patient and clinician. The risk of an adverse event or complication is often described using verbal probability expressions but how these are interpreted by clinicians and patients in the pre-operative setting has not been studied. We asked patients and clinicians to assign a numerical translation (as a percentage) for seven verbal probability expressions in relation to the probability of a major peri-operative complication occurring. In total, data from 290 patients and 57 clinicians were analysed. There was a wide range in percentages assigned by patients to all verbal probability expressions. Patients assigned a wider range of percentage values to each of the verbal probability expressions and these were all significantly higher than those assigned by clinicians: median (IQR [range]) negligible risk 5% (1-15 [0-100]) vs. 0% (0-0 [0-5]); minimal risk 5% (2-10) [0-100]) vs. 1% (0-1 [0-10]); low risk 10% (3-10 [0-100]) vs. 1% (0-2) [0-10]); standard risk 20% (10-40) [0-100]) vs. 1% (1-5) [0-30]); moderate risk 33% (20-50) [0-100]) vs. 5% (3-10) [0-80]); high risk 70% (30-90 [0-100]) vs. 15% (10-40) [1-75]); and very high risk 90% (50-95 [0-100]) vs. 40% (20-50 [5-100]), respectively (p<0.005 for all comparisons). There is considerable variation in the numerical translation of verbal probability expressions by both patients and clinicians. This suggests that verbal probability expressions should not be used in isolation as part of doctor-patient discussions regarding peri-operative risk.

The Differential Effects of Fear and Tranquility on Risk Taking When Probabilistic Information is Communicated in Verbal Terms

Verbal probability expressions are often used to communicate risk in decision making situations. We tested the argument that fear would lead to more pessimistic risk perceptions and higher risk aversion than tranquility when the verbal probability expression used to communicate risk is more (vs. less) ambiguous. In Experiment 1, using a dispute resolution context, we found that fear led to a lower impasse rate than tranquility when the probability of winning in court was described using the ambiguous probability word ‘a chance’ than when less ambiguous probability words were used (i.e., doubtful, probable). In Experiment 2, we replicated this effect using a risky-choice task. Participants in the fear condition were more likely to choose the safe option than those in the tranquil emotion condition when risk was communicated using the ambiguous probability word ‘a chance’ (vs. ‘doubtful’ and ‘probable’). The implications of these findings for emotion, risk taking, and risk communication literatures are discussed.

The Interpretation of "in Context" Verbal Probability Expressions Used in International Financial Reporting Standards - Evidence from Poland

The objective of this paper is to specify which way Polish accounting professionals manage to interpret in context verbal probability expressions (VPEs) from IFRS. Taking into account the Polish accounting professionals attachment to the prudence principle and the Polish mindset, we research here whether they have a conservative approach when interpreting those expressions. For the purpose of our study we distributed a questionnaire and asked a sample of accountants and auditors from Poland to interpret the term probable used IFRS to establish the threshold for recognition of various accounting elements. Our findings provide evidence that the differences interpretation of in context VPEs by Polish accounting professionals exist. We also find that the level of conservatism shared by Polish accountants and auditors affects their individual accounting judgment.

The interpretation of the verbal probability expressions used in the IFRS – The differences observed between Polish and British accounting professionals

Research Question: Do Polish and British accounting professionals interpret verbal probability expressions (VPEs) differently when presented with identical excerpts from IFRS? Motivation: Our research has been motivated by the ongoing debate of consistent interpretation of VPEs. The major difficulty in the interpretation of these terms is the imperative for the accountants to express their individual subjective judgements. Previous research shows that these expressions may have low communication efficiency (Simon, 2002) as they give way to ‘wide variations in interpretation’ (Chesley, 1986: 196). The lack of consistency in the interpretation of VPEs may limit the usefulness of the financial statements prepared on their basis (Simon, 2002). Idea: We examine the interpretational differences between Poles and the British. We also survey whether the principle of prudence will impact the interpretation manner of the Polish and the British accounting professionals. Data: For the purpose of our study we distributed a questionnaire. 332 questionnaires from Poland and 75 questionnaires from the UK included answers that were subject to the analysis. Tools: We asked a sample of professional accountants from Poland and the UK to interpret the “in context” VPEs used in IFRS establishing the threshold for recognition of various accounting elements. Findings: Our results show that there are differences in the manner the Poles and the British interpret VPEs. Additionally, we indicate that the Polish accountants’ attachment to the prudence principle affects their manner of interpretation. However, we were not able to state whether this principle would not affect the level of probability assigned by the British accountants. Contribution: Our paper provides the first comparative results for Poland and the UK, in terms of surveying professional judgement under with relation to the IFRS.

The role of context in the interpretation of verbal probability expressions used in International Financial Reporting Standards

The objective of this study is to specify whether the interpretation of verbal probability expressions (VPEs) by accounting professionals depends on the context in which they have been used in IFRS. For the purpose of this study, a questionnaire was distributed, and a sample of accountants and auditors was asked to interpret the “probable” expression used in IFRS establishing the threshold for recognising various accounting elements. The results provide further support for the hypothesis that the context the VPEs are used in affects their interpretation. The results indicate the problem of inconsistency in the interpretation of these expressions by accounting professionals. Thus, this study should provide some tentative implications for standard setters to consider in using VPEs in IFRS.

Understanding ‘Unlikely (20% Likelihood)’ or ‘20% Likelihood (Unlikely)’ Outcomes: The Robustness of the Extremity Effect

AbstractCalls to communicate uncertainty using mixed, verbal‐numerical formats (‘unlikely [0–33%]’) have stemmed from research comparing mixed with solely verbal communications. Research using the new ‘which outcome’ approach to investigate understanding of verbal probability expressions suggests, however, that mixed formats might convey disadvantages compared with purely numerical communications. When asked to indicate an outcome that is ‘unlikely’, participants have been shown to often indicate outcomes with a value exceeding the maximum value shown, equivalent to a 0% probability —an ‘extremity effect’. Recognising the potential consequences of communication recipients expecting an ‘unlikely’ event to never occur, we extend the ‘which outcome’ work across four experiments, using verbal, numerical, and verbal‐numerical communication formats, as well as a previously unconsidered numerical‐verbal format. We examine how robust the effect is in the context of consequential outcomes and over non‐normal distributions. We also investigate whether participants are aware of the inconsistency in their responses from a traditional ‘how likely’ and ‘which outcome’ task. We replicate and extend previous findings, with preference for extreme outcomes (including above maximum values) observed in both verbal and verbal‐numerical formats. Our results suggest caution in blanket usage of recently recommended verbal‐numerical formats for the communication of uncertainty. Copyright © 2018 John Wiley &amp; Sons, Ltd.

Communicating risk: variability of interpreting qualitative terms

A survey to examine how verbal expressions of probability and magnitude are interpreted was conducted at an international workshop on plant pest risk analysis. Participants were asked to score words and phrases on a scale of 0 to 100 giving minimum and maximum scores. Using hierarchical clustering, expressions describing probability were categorized into three clusters. One homogeneous cluster describes likely probabilities, a second describes unlikely probabilities and a third heterogeneous group contained words that express great uncertainty rather than committing to describe events as likely or unlikely. Hierarchical clustering was also used to group expressions of magnitude into three broad clusters that basically describe small, medium and large. Qualitative risk assessment protocols that prescribe words to represent probabilities and magnitudes should take into account how widely the words can be interpreted. It is suggested that linking verbal probability terms to specific quantitative probabilities would increase transparency and improve risk communication and risk management decision making.

Anchoring climate change communications

Verbal probability expressions (VPEs) are frequently used to communicate risk and uncertainty. The Intergovernmental Panel on Climate Change attempts to standardise the use and interpretation of these expressions through a translation scale of numerical ranges to VPEs. A common issue in interpreting VPEs is the tendency for individuals to interpret VPEs around the midpoint of the scale (i.e. around 50%). Previous research has shown that compliance with the IPCC’s standards can be improved if the numerical translation is presented simultaneously with the VPE, reducing the regressiveness of interpretations. We show that an explicit statement of the lower or upper bound implied by the expression (e.g. 0–33%; 66–100%) leads to better differentiated estimates of the probability implied by ‘likely’ and ‘unlikely’ than when the bound is not explicitly identified (e.g. less than 33%; greater than 66%).

The interpretation differences of verbal probability expressions in principles-based accounting standards: evidence from China

This study examines whether verbal probability expressions (VPEs) in principles-based accounting standards are understood and interpreted consistently by Chinese accounting professionals and students. We gathered data from auditors working in Chinese public accounting firms, accounting professionals not employed by Chinese public accounting firms, and Chinese accounting students. The results indicate that Chinese auditors exhibit a high degree of consensus in their VPE interpretations. However, preparer and student interpretations tend to vary more and exhibit lower levels of consensus. In addition, there are evidences showing that small differences in the translation of VPEs can have a significant unintended impact on the interpretations of these expressions in accounting standards.

Corporate social responsibility audit: Theoretical aspects

This paper puts a conceptual framework to outline research for corporate social responsibility (CSR) audit based on the analysis of current CRS literature and audit models as implementation of CSR. It is intended to make clear the phenomena about the relationship between audit, implementation of business ethics principles and corporate governance. However, most studies do not take into account modify CSR audit. This paper reports part of a research we carried out on the theoretical interpretation of the corporate social responsibility audit. This paper examines the corporate social responsibility audit as a composition of four categories - management system audits, on-site audits, verbal probability expressions (VPE) audits and technology audits. The paper concludes suggests to systematize multiple audits so that they can be conduct in three types of audits - environmental management audits covering in-house companies, environmental technology audits of products, and environmental audits of sites, including non-manufacturing sites and non-consolidated subsidiaries.

Comprehension of the Description of Side Effects in Drug Information Leaflets

The German Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM) states that it uses standardized terms to describe the probabilities of side effects in drug information leaflets. It is unclear, however, whether these terms are actually understood correctly by doctors, pharmacists, and lawyers. A total of 1000 doctors, pharmacists, and lawyers were questioned by mail, and 60.4% of the questionnaires were filled out and returned. In the absence of any particular, potentially suggestive context, the respondents were asked to give a numerical interpretation of each of 20 verbal expressions of probability. Side effects were the subject of a hypothetical physician-patient case scenario. The respondents were also asked to give percentages that they felt corresponded to the terms "common," "uncommon," and "rare." The values obtained were compared with the intended values of the BfArM. The results obtained from the three professional groups resembled each other but stood in marked contrast to the BfArM definitions. With respect to side effects, the pharmacists matched the BfArM definitions most closely (5.8% "common," 1.9% "uncommon" and "rare"), followed by the physicians (3.5%, 0.3%, 0.9%) and the lawyers (0.7%, 0%, 0.7%). When the context of the side effects was not mentioned, the degree of agreement was much lower. Statements about the frequency of side effects are found in all drug information leaflets. Only a small minority of the respondents correctly stated the meaning of terms that are used to describe the frequency of occurrence of side effects, even though they routinely have to convey probabilities of side effects in the course of their professional duties. It can be concluded that the BfArM definitions of these terms do not, in general, correspond to their meanings in ordinary language.

The effect of desirability of the event on verbal expressions of probability

The effect of desirability of the event on verbal expressions of probability

Never say “not”: Impact of negative wording in probability phrases on imprecise probability judgments

Effective translations between numerical and verbal representations of uncertainty are a concern shared by researchers in cognitive science and psychology, with applications to real-world risk management and decision support systems. While there is a substantial literature on such translations for point-wise probabilities, this paper contributes to the scanty literature on imprecise probability translations. Reanalysis of Budescu et al.’s [1] data on numerical interpretations of the Intergovernmental Panel on Climate Change [2] fourth report’s verbal probability expressions (PEs) revealed that negative wording has deleterious effects on lay judgements. Budescu et al. asked participants to interpret PEs in IPCC report sentences, by asking them to provide lower, “best” and upper estimates of the probabilities that they thought the authors intended. There were four experimental conditions, determining whether participants were given any numerical guidelines for translating the PEs into numbers.The first analysis focuses on twelve sentences in Budescu et al. that used the PE “very likely,” “likely,” “unlikely,” or “very unlikely”. A mixed beta regression modelling the lower, “best” and upper estimates revealed a less regressive mean and less dispersion for positive than for negative wording in all three estimates, for both the “very likely” and “likely” sentence sets. The Budescu et al. data also included a task asking for context-free translations of these PEs, and a similar pattern of results was found for that task. Negative wording therefore resulted in more regressive estimates and less consensus regardless of experimental condition.The second analysis focuses on two statements that were positive–negative duals. Appropriate pairs of responses were assessed for conjugacy and additivity. A large majority of respondents were appropriately super- and sub-additive in their lower and upper probability estimates. A mixed beta regression model of these three variables revealed that respondents were suprisingly close to obeying the conjugacy relationships for lower and upper probabilities.

Entrepreneurial Proclivity And The Interpretation Of Subjective Probability Phrases

&lt;p&gt;Verbal expressions of probability are frequently used to describe business and venture opportunities. This research investigates whether entrepreneurs and on-entrepreneurs interpret such expressions differently. We also investigate whether the interpretation of verbal probability expressions is related to the entrepreneurial proclivity of subjects, regardless of whether they are entrepreneurs. The Entrepreneurial Attitude Orientation (EAO) scale was used to measure entrepreneurial proclivity. Fifty-two subjects (17 entrepreneurs and 35 non-entrepreneurs) quantified thirty-five common verbal expressions of probability. The elicited quantifications of the probability phrases were highly variable between individuals, which is consistent with the results reported elsewhere. We found no significant difference between the entrepreneur and non-entrepreneur groups interpretations of the phrases. No meaningful correlations were found between EAO score and probability phrase interpretations. Our results seem to indicate that the interpretation of subjective probability phrases is not related to entrepreneurial proclivity and that the probability phrases involved in the presentation of opportunity are unlikely to affect the way that an entrepreneur perceives that opportunity as opposed to a non-entrepreneur.&lt;/p&gt;