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At least 811 records · Page 45Linked to original sources
PubMed2001

Judgment under emotional certainty and uncertainty: the effects of specific emotions on information processing.

The authors argued that emotions characterized by certainty appraisals promote heuristic processing, whereas emotions characterized by uncertainty appraisals result in systematic processing. The 1st experiment demonstrated that the certainty associated with an emotion affects the certainty experienced in subsequent situations. The next 3 experiments investigated effects on processing of emotions associated with certainty and uncertainty. Compared with emotions associated with uncertainty, emotions associated with certainty resulted in greater reliance on the expertise of a source of a persuasive message in Experiment 2, more stereotyping in Experiment 3, and less attention to argument quality in Experiment 4. In contrast to previous theories linking valence and processing, these findings suggest that the certainty appraisal content of emotions is also important in determining whether people engage in systematic or heuristic processing.

Adult↗
PubMed1996

Mechanisms of visual-spatial attention: resource allocation or uncertainty reduction?

Many studies have found that stimuli can be discriminated more accurately at attended locations than at unattended locations, and such results have typically been taken as evidence for the hypothesis that attention operates by allocating limited perceptual processing resources to attended locations. An alternative proposal, however, is that attention acts to reduce uncertainty about target location, thereby increasing accuracy by decreasing the number of noise sources. To distinguish between these alternatives, we conducted 6 spatial cuing experiments in which target location uncertainty was eliminated. Despite the absence of uncertainty, target discriminations were more accurate at the attended location, consistent with resource allocation models. These cue validity effects were observed under a broad range of conditions, including central and peripheral cuing, but were absent at very short cue-target delay intervals.

Attention↗
PubMed1999

Production uncertainty as a contextual moderator of employee reactions to job design.

A number of authors in the job design field have proposed production uncertainty, the degree to which a qualified incumbent faces unexpected problems in the course of job performance, as a possible moderator of the effectiveness of job design. However, empirical support for this view is limited and has not been explicitly recognized within mainstream job design theory. This study of production operators in a waste water treatment setting provides further empirical support for production uncertainty as a contextual variable influencing job design outcomes, demonstrating that the relationship between job control and affective outcomes (job satisfaction and intrinsic motivation) varies with the level of production uncertainty.

Female↗
PubMed2007

An extension of uncertainty management theory to the self: the relationship between justice, social comparison orientation, and antisocial work behaviors.

A multisource field study of 103 employees and their supervisors tested an extension of uncertainty management theory (E. A. Lind & K. Van den Bos, 2002; K. Van den Bos & E. A. Lind, 2002). According to this theory, persons high in social comparison orientation (F. X. Gibbons & B. P. Buunk, 1999) experience chronic uncertainty about the self. It was hypothesized that this should strengthen the effects of interactional and procedural justice perceptions on antisocial work behaviors. As predicted, the negative relationship between employee perceptions of interactional justice and supervisory ratings of antisocial work behaviors was stronger for people who are high as compared with low in social comparison orientation. Results provide evidence for an extension of uncertainty management theory to the self-domain.

Adult↗
PubMed2002

Origins and estimates of uncertainty in predictions of twenty-first century temperature rise.

Predictions of temperature rise over the twenty-first century are necessarily uncertain, both because the sensitivity of the climate system to changing atmospheric greenhouse-gas concentrations, as well as the rate of ocean heat uptake, is poorly quantified and because future influences on climate-of anthropogenic as well as natural origin-are difficult to predict. Past observations have been used to help constrain the range of uncertainties in future warming rates, but under the assumption of a particular scenario of future emissions. Here we investigate the relative importance of the uncertainty in climate response to a particular emissions scenario versus the uncertainty caused by the differences between future emissions scenarios for our estimates of future change. We present probabilistic forecasts of global-mean temperatures for four representative scenarios for future emissions, obtained with a comprehensive climate model. We find that, in the absence of policies to mitigate climate change, global-mean temperature rise is insensitive to the differences in the emissions scenarios over the next four decades. We also show that in the future, as the signal of climate change emerges further, the predictions will become better constrained.

Journal Article↗
PubMed2004

Quantification of modelling uncertainties in a large ensemble of climate change simulations.

Comprehensive global climate models are the only tools that account for the complex set of processes which will determine future climate change at both a global and regional level. Planners are typically faced with a wide range of predicted changes from different models of unknown relative quality, owing to large but unquantified uncertainties in the modelling process. Here we report a systematic attempt to determine the range of climate changes consistent with these uncertainties, based on a 53-member ensemble of model versions constructed by varying model parameters. We estimate a probability density function for the sensitivity of climate to a doubling of atmospheric carbon dioxide levels, and obtain a 5-95 per cent probability range of 2.4-5.4 degrees C. Our probability density function is constrained by objective estimates of the relative reliability of different model versions, the choice of model parameters that are varied and their uncertainty ranges, specified on the basis of expert advice. Our ensemble produces a range of regional changes much wider than indicated by traditional methods based on scaling the response patterns of an individual simulation.

Journal Article↗
PubMed2001

Sampling design for total and filterable reactive phosphorus monitoring in a lowland stream: considerations of spatial variability, measurement uncertainty and statistical power.

An analysis for spatial variation of phosphorus (P) concentrations in the dissolved and particulate compartments of Latrobe River water in Victoria, Australia is described. Water sampling was based on a nested hierarchical design and variation was measured at different spatial scales. Total variance of the dissolved and particulate P compartments was partitioned using analysis of variance (ANOVA) to determine the spatial scale that requires most sampling effort. Statistical power analysis was used to determine the optimum sample size for the spatial scale. An uncertainty budget was estimated from sampling and analytical uncertainty. Ten and twelve samples, at the smallest spatial scale, required the greatest sampling effort, and led to the greatest required statistical power for the determination of dissolved and particulate P, respectively, in the Latrobe River catchment. The results emphasize the need for aquatic chemists to be aware of the ramifications of different types of uncertainty and variance in environmental studies.

Environmental Monitoring↗
PubMed1995

Uncertainties in the teaching of ethics to students of nursing.

Whilst ethics is now commonplace on nursing curricula in the United Kingdom there remains doubt as to how and what to teach. This doubt has its origins in interlinked uncertainties within nursing, ethics and education. In nursing there are uncertainties about whether we are teaching ethics to professionalize or because we are a profession, and about whether there is something which is uniquely 'nursing ethics'. In ethics there are competing paradigms of ethical theory and competing theories of moral development. In education there are competing epistemologies, theories of learning and models of curriculum planning. These uncertainties are interlinked and an understanding of them will help clarify the debate as to what to teach and how to teach it.

Curriculum↗
PubMed2001

Measuring parental uncertainty during the diagnosis phase of serious illness in a child.

The purpose of this study was to revise and evaluate the Parental Perception of Uncertainty Scale (PPUS) for use in measuring parental uncertainty during the diagnosis of serious illness in a child. The concept of parental uncertainty during diagnosis was elaborated and original PPUS items were revised based on a review of the literature. Content validity of the revision was judged by nurse and parent experts. Preliminary psychometric evaluation of the measure was conducted in a sample of 25 biological mothers of infants who are HIV seropositive. The results offer initial support for the reliability and validity of the revised instrument.

Adult↗
PubMed2006

Analysis of uncertainties in polymer viscoelastic properties obtained from equilibrium computer simulations.

We critically evaluate the uncertainties in the stress autocorrelation function obtained from equilibrium molecular dynamics simulation of model polymer melts. This quantity is central to evaluating transport properties, e.g., the complex modulus and the viscosity. In contrast to the intuitive expectation that simulations have to be run five to six orders of magnitude longer than the chain relaxation time to reduce uncertainties to acceptable levels, our analysis shows that the majority of the uncertainty is associated with rapidly oscillating bonded interactions. These fluctuations occur on time scales which are approximately 10(4) times shorter than the relaxation time of a chain of length 80. Consequently, the effects of these oscillations on the stress autocorrelation function can be dramatically reduced by (i) conducting long simulations (typically 10(6) times longer than the bond relaxation times or only 10(2) chain relaxation times) and (ii) by performing running averages with time windows whose time scales are much longer than these oscillations. Conducting such long simulations also allows for the accurate determination of the melt viscosity and the low-frequency complex modulus, but performing running averages do not impact these quantities since they are time integrals of the stress autocorrelation function.

Journal Article↗
PubMed1988

The effect of feature uncertainty on spatial discriminations.

Just noticeable differences (JNDs) in orientation and spatial frequency were measured under two conditions. In one condition the subject was cued before stimulus presentation as to the feature to be discriminated on that trial, while in the other condition the subject was cued only after stimulus offset. JNDs were larger in the latter, feature uncertainty, condition. This feature uncertainty effect increased with decreasing stimulus processing time. The results suggest that this feature uncertainty effect is of sensorial origin. They also demonstrate that it is possible for humans to address selectively those mechanisms that are most relevant for a given discrimination task.

Adult↗
PubMed2003

Uncertainty orientation in the group context: categorization effects on persuasive message processing.

Persuasive messages often originate from in-group or out-group sources. Theoretically, in-group categories could facilitate heuristic-based message processing (because of the attractiveness of in-groups and their social reality cues) or systematic-based processing (because of high personal relevance of the message). The authors expected individual differences in uncertainty orientation and socially based expectancy congruence to be important variables in understanding these processes. Participants were exposed to strong or weak, in-group or out-group messages that were either expectancy congruent (in-group agreement, out-group disagreement) or expectancy incongruent (in-group disagreement, out-group agreement). As predicted, uncertainty-oriented participants increased systematic information processing under incongruent conditions relative to congruent (i.e., relatively certain) conditions; certainty-oriented individuals processed systematically only under congruent conditions. These findings suggest that uncertainty that has been created through social-categorization conflicts is treated differently by people of different personality styles.

Adult↗
PubMed1998

Terminological problems around "accuracy" and "uncertainty".

The consistent description and treatment of metrological data in laboratory medicine are hampered by the lack of a systematic, universally accepted nomenclature and by variations in the conceptual understanding of uncertainty. The differences between the classical approach to a result as consisting of a true value plus errors and the new approach of a measured corrected value with uncertainty based on a detailed uncertainty budget are discussed. The various definitions of some relevant concepts, including "accuracy", the new concept "trueness", and "precision", are contrasted, and proposed modification are presented.

Bias↗
PubMed1999

Quality specifications based on the uncertainty of measurement.

The result of a measurement needs to be accompanied by information on the error or uncertainty of the measurement. Either of two very closely related concepts is thus required to indicate the usefulness and relevance of a result for its purpose: decision making. This presentation will outline the difference between the concept of error and that of uncertainty and deal with procedures to estimate the latter. The use of a spreadsheet program will illustrate how the combined uncertainty is estimated in a relatively complex situation with a bearing on laboratory medicine.

Calibration↗
PubMed1999

Setting quality specifications for the future with newer approaches to defining uncertainty in laboratory medicine.

When describing the performance of procedures and the reliability of their results, ISO terminology should be used. Results should be universally comparable and this requires metrological traceability. The concomitant uncertainty (inversely) indicating reliability should be obtained in a universal and transparent fashion, and should be combinable. Therefore, the approach of the "Guide to the expression of uncertainty in measurement", leading to a result without known bias and a combined standard uncertainty, has advantages over the allowable total error concept, incorporating procedural bias.

Calibration↗
PubMed1977

Psychological differentiation, event uncertainty, and heart rate.

Psychological differentiation and uncertainty about receiving a painful noise were examined for their effects on heart rate during the anticipatory, impact and recovery phases of the tone presentation. Psychologically differentiated and nondifferentiated subjects were randomly assigned to three event uncertainty conditions (5 percent, 50 percent, 95 percent probability of noise). Subjects were informed of the probability of receiving the noise, as well as the time of occurrence as indicated by a sequentially numbered visual display. Subjects received the noise on the second of the experiment's two trials. Cognitive style and event uncertainty interacted during the anticipatory phase--i.e., differentiated subjects showed a monotonic increase in heart rate with increasing probability of receiving the noise that represents preparation for instrumental activity. Results are consistent with the theory that meaningful personality-stress relationships may be obtained when examining stimulus-oriented dispositions.

Acoustic Stimulation↗
PubMed2004

Quantifying uncertainties in the assessment of sediment quality: statistical criteria and guidelines for sediment quality assessments.

Current sediment quality guidelines generally adopt a tiered approach in order to assess sediment quality more cost-effectively. The uncertainties involved in the tiered approach of an integrative assessment, however have not been quantified resulting in a risk of committing type I error or type II error at the final confirmatory stage. This study develops statistical criteria and guidelines for the sediment chemistry component of an integrative assessment of sediment quality. At the tier 1 screening stage, historical data or an initial survey is required to determine the minimum sample numbers that will be required to be representative of the study site. Understanding the guiding principles which have underpinned the setting of sediment quality criteria for contaminant is an important factor in tier 1 evaluations. To reduce cost and uncertainty in data, sampling should include the least number of samples necessary to minimise uncertainties by estimating the probability distribution function (which represents the variability of the natural environment at the location of concern), with subsequent application of kriging and sequential simulation methods on data obtained. Implementation of statistical criteria and guidelines in sediment quality assessments can provide a foundation for a further quantitative cost/benefit analysis and decrease the risk of committing type I and type II statistical errors at later classification stages.

Environmental Monitoring↗
PubMed1998

Managing the uncertainties of low-level radioactive waste disposal.

The disposal of low-level radioactive waste (LLRW) entails financial and safety risks not common to most market commodities. This manifests debilitating uncertainty regarding future waste volume and disposal technology performance in the market for waste disposal services. Dealing with the publicly perceived risks of LLRW disposal increases the total cost of the technology by an order of magnitude, relative to traditional shallow land burial. Therefore, this analysis first examines five proposed disposal facility designs and quantifies the costs associated with these two important sources of uncertainty. Based upon this analysis, a marketable disposal permit mechanism is proposed and analyzed for the purpose of reducing market uncertainty and thereby facilitating a market solution to the waste disposal problem. In addition to quantifying the costs, the results illustrate the ways in which the design of a technology is influenced by its institutional environment, and vice versa.

Costs and Cost Analysis↗