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A regression model was tested to examine the relation between uncertainty about choice of study and regulation activities in three groups of freshmen (N = 566). Invariance of regression coefficients, intercept, and residual error terms over groups was found. The strongest explanatory variable of uncertainty about choice of study was lack of regulation.
In a classic study, Buss, Larson, Westen, and Semmelroth found that men were more distressed by the thought of a partner's sexual infidelity (labeled sexual jealousy) and women were more distressed by the thought of a partner's emotional infidelity (labeled emotional jealousy). Buss and his associates explained the results by suggesting that men are concerned about uncertainty of paternity, that is, the possibility of raising another man's child while believing that the child is their own. To test this explanation, the Desire for Children Scale was created. Its internal consistency and test-retest reliabilities were .86 and .89, respectively. Scores correlate with stated Number of Children Desired (convergent validity) but none of the Big-Five traits (divergent validity). It was hypothesized that for men scores on this scale would correlate positively with scores on sexual jealousy. The Desire for Children Scale and the two Sexual vs Emotional Jealousy items of Buss and his associates were given to 49 men and 55 women college students enrolled in psychology courses. Their average age was 19.9 yr. (SD= 3.7), and average year in school was 2.0 (SD= 1.2). Subjects volunteered to participate in the study in exchange for course credit. The hypothesis was confirmed and gives support to the uncertainty of paternity explanation.
Two experiments involving paired comparisons of numerical and nonnumerical expressions of uncertainty are reported. Subjects were timed under two opposing sets of instructions ("choose higher probability" vs. "choose lower probability"). Numerical comparisons were consistently faster and easier than their nonnumerical counterparts. Consistent distance and congruity effects were obtained, illustrating that both numerical and nonnumerical expressions of uncertainty contain subjective magnitude information, and suggesting that similar processes are employed in manipulating and comparing numerical and verbal terms. To account for the general pattern of results obtained, Holyoak's reference point model (1978) was generalized by explicitly including the vagueness of the nonnumerical expressions. This generalized model is based on the notion that probability expressions can be represented by membership functions (Wallsten, Budescu, Rapoport, Zwick, & Forsyth, 1986) from which measures of location for each word, and measures of overlap for each pair can be derived. A good level of fit was obtained for this model at the individual level.
Although patient exposure has been increasing in recent years, few institutions have dosimeters and are able to ascertain patients' exposure dose. Internationally, however, it is necessary to adopt safety levels for patient exposure doses, and guidance levels have been introduced. Therefore, the need for measurement in areas of x-ray diagnosis has been increasing. As a result, several societies concerned with radiation dose have been endeavoring to establish a calibration system of radiation measurement and a dosimeter calibration system, which are the basics of radiation protection. Ten regional centers for standardization of doses in x-ray diagnosis were established and have begun trials relating to dosimeter cross calibration. Our institution, as one of these centers, has instituted a trial. In this study, the cross-calibration field, the reliability of the cross-calibration skill of our regional center, and the standard uncertainty of cross calibration were investigated. As a consequence of the investigation, it was determined that our cross-calibration field follows the protocol of the Japanese Society of Radiological Technology, the difference between calibration factor/cross calibration factor obtained by JQA and our regional center is within 2.5%, and the expanded uncertainty of our cross calibration is about 7.2% (k=2).
This study addressed the pattern of small organizations' adaptation responses to uncertainty in the regulatory and competitive sectors of their environment using data from physicians in solo practice. An existing general model of adaptation was modified to reflect small-firm work processes. The result is a four-cell model that distinguishes adaptive strategies in terms of their functional orientations and how firms pursue them--whether alone or in collaboration with other firms. Data analyses supported the propositions that adaptation in small firms is a multicomponent construct and that regulatory and competitive uncertainty differentially influence the adaptation process. Although individual relationships found among the sets of adaptation activities supported the contention that adaptation choices follow a hierarchical cost pattern, the overall fit of the model suggests modification of the theory in subsequent research efforts.
A change in payment system of general practitioners from capitation to a mix of one-half capitation and one-half fee for service in Copenhagen, Denmark, resulted in a significant overall increase in diagnostic and curative services. The rate of increase differs between services. In this article, it is assumed that the rate of increase varies with doctors' professional uncertainty relative to the services studied. Professional uncertainty is measured as the degree to which performances of a service are determined by diagnoses made. The data validate the measure given the assumption.
Dichotic digit listening was made more difficult by interleaving one-, two-, three-, and four-pair digits within a test list in which the subjects did not know a priori the number of digit pairs presented on a given trial, thereby introducing listener uncertainty. Twenty right-handed (mean age = 26.8 years) and 20 left-handed adults (mean age = 24.0) with normal hearing and 40 right-handed adults in the 60- to 75-years age range (mean age = 67.2) with mild-to-moderate sensorineural hearing loss were evaluated. Compared to traditional paradigms, the uncertainty of stimulus length (one, two, three, or four pairs) reduced overall recognition performance on stimuli presented to both ears of all groups, but the reduction was more pronounced for the left ear than for the right ear. The recognition performance of the right-handed subjects was more homogeneous than the performance of the left-handed subjects. In comparison to the young subjects, the 60- to 75-year-old group had substantially reduced recognition performance.
This qualitative research study uses a phenomenological approach to understand the significant of uncertainty and hope in seropositive women and to determine the link between the two. Four seropositive women with children make up the sample. The findings illustrate that uncertainty can be divided into nine themes; reactions on learning or seropositivity; the unknowns of seropositive; the feeling that time and the future are limited; the law of silence; concerns about children; concerns about people withdrawing; concerns about intimate relationships; the image of people living with HIV, and the difficulty experiencing loss--especially loss of control over one's life. The findings also illustrate that hope can be divided into seven themes: seeking assistance through self-help groups; coherence with children; the changing perception of seropositivity; developing relationships with others living with HIV; the fight against HIV; a personal commitment to wellness; and new life experiences and spiritual growth. These findings could be used to determine measures to improve the well-being and health of seropositive women. The authors make recommendations for nursing practice.
Neglect of probability prognosis orients the theory of functional systems to description of rigidly determined forms of behavior (congenital behavior, frontal syndrome, etc.). The authors suggest an original concept for analysis of behavior under conditions of subjective uncertainty based on probability estimations. It contains all classical components of a behavioral act model developed by P. K. Anokhin. The role of probability prognosis at the stages of making decision (purpose) and formation and realization of the program of actions is argued. Two new components are added to the classical model: memory buffer and system of making probabilistic decision for modifying the program of actions. Such an approach essentially extends the potentialities of using the theory of functional systems, making it usable not only for rigidly determined behavior but for behavior under conditions of subjective uncertainty.
Monte Carlo simulations taking uncertainty in model parameters into account were performed on a river water quality model. The simulation results were used to rank wastewater treatment plant control strategies according to their impacts on river water quality. This impact is estimated by the maximum ammonium concentration and by the duration of dissolved oxygen concentration below 4 g/m3 at the downstream boundary of the system. The strategies were classified according to the previous criteria using 4 ranking methods, one of them being based on the concept of stochastic dominance. Results are presented for a case study based on a 10 km stretch of the River Cam as it passes through the city of Cambridge in Eastern England. It was found that ranking was robust in face of uncertainty in the parameter values for the control strategies considered as being superior in terms of river water quality impacts.
Background The increasing use of the methods of evidence-based medicine to keep up-to-date with the research literature highlights the absence of high-quality evidence in many areas in psychiatry. Aims To outline current uncertainties in the maintenance treatment of bipolar disorder and to describe some of the decisions involved in designing a large simple trial. Method We describe some of the strategies of evidence-based medicine, and how they can be applied in practice, focusing specifically on the area of bipolar disorder. Results One of the key clinical uncertainties in the treatment of bipolar disorder is the place of maintenance drug treatments and their relative efficacy. A large-scale study, the Bipolar Affective DISORDER: Lithium Anticonvulsant Evaluation (BALANCE) trial, is proposed to compare the effectiveness of lithium, valproate and the combination of lithium and valproate. Conclusions Providing reliable answers to key clinical questions in psychiatry will require new approaches to clinical trials. These will need to be far larger than previously appreciated and will therefore need to be collaborative ventures involving front-line clinicians.
BACKGROUND: The increasing use of the methods of evidence-based medicine to keep up-to-date with the research literature highlights the absence of high-quality evidence in many areas in psychiatry. AIMS: To outline current uncertainties in the maintenance treatment of bipolar disorder and to describe some of the decisions involved in designing a large simple trial. METHOD: We describe some of the strategies of evidence-based medicine, and how they can be applied in practice, focusing specifically on the area of bipolar disorder. RESULTS: One of the key clinical uncertainties in the treatment of bipolar disorder is the place of maintenance drug treatments and their relative efficacy. A large-scale study, the Bipolar Affective Disorder: Lithium Anticonvulsant Evaluation (BALANCE) trial, is proposed to compare the effectiveness of lithium, valproate and the combination of lithium and valproate. CONCLUSIONS: Providing reliable answers to key clinical questions in psychiatry will require new approaches to clinical trials. These will need to be far larger than previously appreciated and will therefore need to be collaborative ventures involving front-line clinicians.
In the 1940s and 1950s, over 20,000 children in Israel were treated for tinea capitis (scalp ringworm) by irradiation to induce epilation. Follow-up studies showed that the radiation exposure was associated with the development of malignant thyroid neoplasms. Despite this clear evidence of an effect, the magnitude of the dose-response relationship is much less clear because of probable errors in individual estimates of dose to the thyroid gland. Such errors have the potential to bias dose-response estimation, a potential that was not widely appreciated at the time of the original analyses. We revisit this issue, describing in detail how errors in dosimetry might occur, and we develop a new dose-response model that takes the uncertainties of the dosimetry into account. Our model for the uncertainty in dosimetry is a complex and new variant of the classical multiplicative Berkson error model, having components of classical multiplicative measurement error as well as missing data. Analysis of the tinea capitis data suggests that measurement error in the dosimetry has only a negligible effect on dose-response estimation and inference as well as on the modifying effect of age at exposure.
An analysis system of informational uncertainties for accidental risk assessment of chemicals is introduced. Statistical test methods and fuzzy sets method can do the quantitative analysis of the input parameters. The uncertainties of the model can be used by quantitative compared method for the leakage accidents of chemicals. The estimation of the leaking time is important for discussing accidental source term. The uncertain analyses of the release accident for pipeline gas (CO) liquid chlorine and liquid propane gas (LPG) have been discussed.
Proficiency test results from 5 countries involving 61 separate interlaboratory proficiency tests for pesticide residues were examined in this study. A total of 24 different matrixes and 869 relative standard deviations of the mean (or median) pesticide residue concentration were statistically evaluated in relation to the Horwitz function. The aim was to determine whether or not the concentration-dependent relationship described by Horwitz would hold for the much narrower range of chemicals and concentrations covered in routine pesticide residue analysis. Although for fatty (animal-derived) matrixes the variability increased as the concentration decreased in line with the Horwitz equation, the between-laboratories relative standard deviations for nonfatty matrixes (fruit, vegetables, and grain) remained at 25% over the entire concentration range of 1 microg/kg to 10 mg/kg for the pesticides studied. Given these findings, the Horwitz equation remains valid for calculating uncertainties involving pesticide residues in fatty matrixes. However, for pesticide residue analyses involving nonfatty matrixes, a constant relative standard deviation of 25% is more appropriate for calculating uncertainties, particularly when a reported result is assessed against a regulatory limit.
Uncertainty in screening has consequences for real people's lives. This article describes the various types of uncertainty, such as false results, diagnostic probabilities, consistency in diagnosing, bias in screening research, cumulative risk of false results over a life span, and the potential risk with certain procedures. Overdiagnosis as an unrecognised cause of harm in screening is also discussed. Every offer of a screening contains a hidden message, saying: "you are not able to assess your own health; even if you think you are healthy, you may have an unknown disease". Hence, the worst effect of screening might be the undermining of people's confidence in their ability to assess their own health. If the concept of screening conveys the idea in the population that only medical examinations can say anything about health status, it implies the use of many other activities in the health care system to convince healthy people that they are still healthy.
This study illustrates the impact of address geocoding uncertainty on rural estimates of reportable disease incidence using campylobacteriosis as an example. After all cases of campylobacteriosis notified from 1993 to 1997 had been geocoded, the minimum and maximum disease notification rates were calculated for rural and urban areas of New Zealand. The estimated maximum rural rates were four times higher than estimated minimum rural rates, whereas estimated minimum and maximum urban rates varied minimally. The impact of address geocoding on the estimation of disease notification rates across Public Health Service Regions showed considerable variation. The relative proportions of ungeocoded notifications to rural notifications ranged from 1.3:1 to 10.2:1, reflecting the range of uncertainty in estimated rural rates of campylobacteriosis. Unless the reliability of captured rural address data is improved significantly, disease surveillance systems will underestimate rural rates of disease and limit small area analyses.
"When using population forecasts it is important to take into account the degree of uncertainty of the results. For that reason the Netherlands Central Bureau of Statistics publishes low and high variants next to the most probable medium variant.... The width of the interval between the variants is based on an analysis of previous forecast errors. The degree of uncertainty of the various forecast results turns out to vary strongly.... On the basis of a statistical time-series model of forecast errors of total population growth, a confidence interval of total population size can be estimated."