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Gold prices have been of major interest for a lot of investors, analysts, and economists. Accordingly, a number of different modeling approaches have been used to forecast gold prices. In this manuscript, the geometric Brownian motion approach, used in the pricing of numerous types of assets, is used to forecast the prices of gold at yearly, monthly, and quarterly frequencies. This approach allows for simulating one-period-ahead prices and the associated probabilities. The expected prices obtained from the simulated prices and probabilities are found to provide reliable forecasts when compared with the observed yearly, monthly, and quarterly prices. [ABSTRACT FROM AUTHOR]

Denić (2018, 2019, To appear) observes that the availability of distributive inferences—for sentences with disjunction embedded in the scope of a universal quantifier—depends on the size of the domain quantified over as it relates to the number of disjuncts. Based on her observations, she argues that probabilistic considerations play a role in the computation of implicatures. In this paper we explore a different possibility. We argue for a modification of Denić's generalization, and provide an explanation that is based on intricate logical computations but is blind to probabilities. The explanation is based on the observation that when the domain size is no larger than the number of disjuncts, universal and existential alternatives are equivalent if distributive inferences are obtained. We argue that under such conditions a general ban on 'fatal competition' (Magri 2009a,b, Spector 2014) is activated, thereby predicting distributive inferences to be unavailable. [ABSTRACT FROM AUTHOR]

Copyright of Quetes Litteraires is the property of Katolicki Uniwersityt Lubelski Jana Pawla II, Wydzial Nauk Humanistycznych, Institut Filologii Romaj and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Demographers and other social scientists often study effect heterogeneity (defined here as differences in outcome-predictor associations across groups defined by the values of a third variable) to understand how inequalities evolve between groups or how groups differentially benefit from treatments. Yet answering the question "Is the effect larger in group A or group B?" is surprisingly difficult. In fact, the answer sometimes reverses across scales. For example, researchers might conclude that the effect of education on mortality is larger among women than among men if they quantify education's effect on an odds-ratio scale, but their conclusion might flip (to indicate a larger effect among men) if they instead quantify education's effect on a percentage-point scale. We illuminate this flipped-signs phenomenon in the context of nonlinear probability models, which were used in about one third of articles published in Demography in 2018-2019. Although methodologists are aware that flipped signs can occur, applied researchers have not integrated this insight into their work. We provide formal inequalities that researchers can use to easily determine if flipped signs are a problem in their own applications. We also share practical tips to help researchers handle flipped signs and, thus, generate clear and substantively correct descriptions of effect heterogeneity. Our findings advance researchers' ability to accurately characterize population variation. [ABSTRACT FROM AUTHOR]

The notion focus affinity refers to the likelihood that a grammatical role (e.g., subject, object) is the narrow focus of a sentence. There is evidence that such differences exist at the level of distributional data. For example, subjects are less often focal and more often topical as compared to direct objects. However, it is not obvious whether focus affinity is genuinely related to grammatical roles. Focus affinity could be an epiphenomenon of various other linguistic and pragmatic processes or their interactions (e.g., direct objects are more often indefinite, less often animate, more often new than subjects). In our controlled experimental study, we investigate the focus affinity of three adjunct types (instruments, locatives, depictive secondary predicates) in Spanish and provide evidence that these grammatical roles indeed differ with respect to focus affinity. Depictives show the highest degree of focus affinity, followed by instruments and finally locatives. These effects are robust and stable even if we account for a number of possible alternative explanations. Thus, we suggest that focus affinity is a property sufficiently closely associated with grammatical roles to justify more attention both in theoretical linguistic and psycholinguistic literature. • Focus affinity is an understudied information structural concept. • Focus affinities of three adjunct types have been experimentally investigated. • Focus hierarchy: Depictives > Instruments > Locatives. • Differences between grammatical roles are robust even if we consider alternative explanations (e.g., probabilities). [ABSTRACT FROM AUTHOR]

Copyright of Revista Habanera de Ciencias Médicas is the property of Universidad de Ciencias Medicas de La Habana and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Methods for group comparisons using predicted probabilities and marginal effects on probabilities are developed for regression models for binary outcomes. Unlike approaches based on the comparison of regression coefficients across groups, the methods we propose are unaffected by the scalar identification of the coefficients and are expressed in the natural metric of the outcome probability. While we develop our approach using binary logit with two groups, we consider how our interpretive framework can be used with a broad class of regression models and can be extended to any number of groups. [ABSTRACT FROM AUTHOR]

Copyright of Journal of The Iraqi University is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article examines a specific task (task 6) of the National external assessment in Mathematics at the end of 7th grade, conducted in June 2020. A brief analysis of the performance of students across the country by districts of this task was made. The task itself is in the field of competence "Elements of probabilities and statistics" from the mathematics curriculum for 6th grade. It explores the concept of "probability of a random event" and is analogous to task 7 of the National external assessment in Mathematics in the previous 2018/2019 school year. The competencies are analyzed as expected results from the quality assimilation of the study material. The topic "Elements of Probabilities and Statistics" is part of the new curriculum of Mathematics programs in lower secondary education, which are part of the education reform after the entry into force of the new Pre-school and School Education Act in 2016 in Bulgaria. In the previous 2018/2019 school year, the students, who took part in the External assessment in Mathematics achieved poor performance in a task similar to the one presented. Then it was assumed that the preparation of students on this topic is probably not good or that students are taught to solve certain types of tasks and can not go beyond the framework. Then the questions were raised whether one of the reasons could be the poor presentation of students' learning content by teachers, where they find it difficult to learn the concepts and further difficult to build competencies on the topic. The difficulties of the teachers themselves could be caused by the fact that this new content has not been taught by them so far and they do not feel confident enough to teach it. Another reason is that teachers still do not know how to plan their work well enough and continue to teach verbatim in textbooks, without considering whether the textbooks offer does not exceed the content of the curriculum, and students in most cases have no interest in the subject and have significant knowledge gaps from previous years. Thus, every school and every teacher had to look for the reasons for the achieved results of the external assessment during the last school year, as well as ways to solve them and take action for the next school year. As a result, in the 2019/2020 school year, the task that tested the concept of "probability of a random event" there was a large percentage of students who answered correctly. Ie it has become a recognizable and expected task, but some of the reasons seek their solution. In recent years, steps have been taken to establish not only the mathematical literacy of students at the end of seventh grade, but also their functional literacy in Bulgarian language. In the coming years, a study of literacy and subjects will be tested, which will participate integrated in the National external assessment for the recent year. [ABSTRACT FROM AUTHOR]

The mental model theory postulates that the meanings of conditionals are based on possibilities. Indicative conditionals—such as "If he is injured tomorrow, then he will take some leave"—have a factual interpretation that can be paraphrased as It is possible, and remains so, that he is injured tomorrow, and in that case certain that he takes some leave. Subjunctive conditionals, such as, "If he were injured tomorrow, then he would take some leave," have a prefactual interpretation that has the same paraphrase. But when context makes clear that his injury will not occur, the subjunctive has a counterfactual paraphrase, with the first clause: It was once possible, but does not remain so, that he will be injured tomorrow. Three experiments corroborated these predictions for participants' selections of paraphrases in their native Spanish, for epistemic and deontic conditionals, for those referring to past and to future events, and for those with then clauses referring to what may or must happen. These results are contrary to normal modal logics. They are also contrary to theories based on probabilities, which are inapplicable to deontic conditionals, such as, "If you have a ticket, then you must enter the show." [ABSTRACT FROM AUTHOR]

Objectives: Sex is usually not estimated in skeletonized non‐adult individuals because sexual dimorphism is considered minimal before puberty. In 2017, a new approach based on the shape of the auricular surface was proposed, showing that this anatomic area of the ilium is dimorphic. This study tests the reproducibility and evaluates the accuracy of the method in a bigger sample. Materials and Methods: Thirty males and 31 females from the Lisbon Collection (1 day–18 years old) were analyzed by two researchers, one experienced, and the other without previous knowledge of the method. The sample was divided into three groups according to prepubertal and pubertal hormonal peaks (<2, 0–12, and 13–18 years old). Two metric variables (DE/AD and FI/CF ratios), two morphological features (Overall Morphology, OM and Morphology of the Retroauricular End of the Superior Demiface, MRS), and two formulae were tested based on the adequate results obtained in the original article. Results: Data shows a low interobserver error (ICC > 0.92; K > 0.74). Morphological features provide better results than the metrics (DE/AD = 77.05%; FI/CF = 73.77%; OM = 80.33%; MRS = 85.24%). The discriminant function correctly classified 86.66% of the males and the logistic regression, 83.33%. The method was equally reliable in 0–12 and 13–18 years‐old age groups and more accurate in males. The accuracy of most of the variables reached 100% for males under 2 years‐old, and the probabilities were higher than for older individuals. The percentages of correct estimations are not influenced by the age, year, and cause of death. Discussion: Despite the relatively small sample size, this study confirms the usefulness of the auricular surface for non‐adult sexual estimation, especially for those younger than 2 years old. Additional validation tests in documented individuals from other geographic regions are suggested. [ABSTRACT FROM AUTHOR]

Safety analysis of high confidence systems requires guaranteed bounds on the probabilities of events of interest. Establishing the correctness of algorithms that aim to compute such bounds is challenging. We address this problem in three steps. First, we use monadic transition systems (MTS) in the category of sets as a framework for modeling discrete time systems. MTS can capture different types of system behaviors, but we focus on a combination of non-deterministic and probabilistic behaviors that often arises when modeling complex systems. Second, we use the category of posets and mono-tonic maps as a setting to define and compare approximations. In particular, for the MTS of interest, we consider approximations of their configurations based on complete lattices. Third, by restricting to finite lattices, we obtain algorithms that compute over-approximations, i.e., bounds from above within some partial order of approximants, of the system configuration after n steps. Interestingly, finite lattices of "interval probabilities" may fail to accurately approximate configurations that are both non-deterministic and probabilistic, even for deterministic (and continuous) system dynamics. However, better choices of finite lattices are available. [ABSTRACT FROM AUTHOR]

Changing the information format from probabilities into frequencies as well as employing appropriate visualizations such as tree diagrams or 2 × 2 tables are important tools that can facilitate people's statistical reasoning. Previous studies have shown that despite their widespread use in statistical textbooks, both of those visualization types are only of restricted help when they are provided with probabilities, but that they can foster insight when presented with frequencies instead. In the present study, we attempt to replicate this effect and also examine, by the method of eye tracking, why probabilistic 2 × 2 tables and tree diagrams do not facilitate reasoning with regard to Bayesian inferences (i.e., determining what errors occur and whether they can be explained by scan paths), and why the same visualizations are of great help to an individual when they are combined with frequencies. All ten inferences of N = 24 participants were based solely on tree diagrams or 2 × 2 tables that presented either the famous "mammography context" or an "economics context" (without additional textual wording). We first asked participants for marginal, conjoint, and (non-inverted) conditional probabilities (or frequencies), followed by related Bayesian tasks. While solution rates were higher for natural frequency questions as compared to probability versions, eye-tracking analyses indeed yielded noticeable differences regarding eye movements between correct and incorrect solutions. For instance, heat maps (aggregated scan paths) of distinct results differed remarkably, thereby making correct and faulty strategies visible in the line of theoretical classifications. Moreover, the inherent structure of 2 × 2 tables seems to help participants avoid certain Bayesian mistakes (e.g., "Fisherian" error) while tree diagrams seem to help steer them away from others (e.g., "joint occurrence"). We will discuss resulting educational consequences at the end of the paper. [ABSTRACT FROM AUTHOR]

Trajectory reconstruction in bloodstain pattern analysis is currently performed by assuming that blood drop trajectories are straight along directions inferred from stain inspection. Recently, several attempts have been made at reconstructing ballistic trajectories backwards, considering the effects of gravity and drag forces. Here, we propose a method to reconstruct the region of origin of impact blood spatter patterns that considers fluid dynamics and statistical uncertainties. The fluid dynamics relies on defining for each stain a range of physically possible trajectories, based on known physics of how drops deform, both in flight and upon slanted impact. Statistical uncertainties are estimated and propagated along the calculations, and a probabilistic approach is used to determine the region of origin as a volume most compatible with the backward trajectories. A publicly available data set of impact spatter patterns on a vertical wall with various impactor velocities and distances to target is used to test the model and evaluate its robustness, precision, and accuracy. Results show that the proposed method allows reconstruction of bloodletting events with distances between the wall and blood source larger than ∼1 m. The uncertainty of the method is determined, and its dependency on the distance between the blood source and the wall is characterized. Causes of error and uncertainty are discussed. The proposed method allows the consideration of stains indicating impact velocities that point downwards, which are typically not used for determining the height of the origin. Based on the proposed method, two practical recommendations on crime scene documentation are drawn. [ABSTRACT FROM AUTHOR]

Past research has revealed a trend effect when people are faced with a revised probabilistic forecast: A forecasted event that has become more (vs. less) certain is taken to signal a trend toward even stronger (weaker) certainty in future revisions of the forecast. The present paper expands this finding by exploring the boundary conditions of the trend effect and how it affects judgments of the forecaster. In Study 1, the trend effect was shown to persist when receivers process the forecast more deliberately, by considering reasons for the revision. In Study 2, trend continuation was predicted even when the two forecasts were made by different experts at different points in time. Study 3 demonstrated that the effect disappears when receivers are given an earlier forecast disrupting the linearity of the trend (e.g. a 60–70% sequence preceded by a 70% forecast). In Study 4, two forecasters were perceived as more in agreement when revising divergent probabilities in the same rather than in opposite directions. If the event occurs, a forecast with downgraded probability (e.g. from 50 to 40%) was judged to be less accurate than an equally uncertain single forecast (40%). These results demonstrate the robustness of the trend effect based on two forecasts, affecting not only receivers' expectations of what comes next, but also their perceptions of the forecaster and of forecast accuracy. The findings have implications for how people communicate and understand risks and other uncertain events in areas such as climate science, weather prediction and societal risk assessments. [ABSTRACT FROM AUTHOR]

For more than 20 years, research has proven the beneficial effect of natural frequencies when it comes to solving Bayesian reasoning tasks (Gigerenzer and Hoffrage, 1995). In a recent meta-analysis, McDowell and Jacobs (2017) showed that presenting a task in natural frequency format increases performance rates to 24% compared to only 4% when the same task is presented in probability format. Nevertheless, on average three quarters of participants in their meta-analysis failed to obtain the correct solution for such a task in frequency format. In this paper, we present an empirical study on what participants typically do wrong when confronted with natural frequencies. We found that many of them did not actually use natural frequencies for their calculations, but translated them back into complicated probabilities instead. This switch from the intuitive presentation format to a less intuitive calculation format will be discussed within the framework of psychological theories (e.g., the Einstellung effect). [ABSTRACT FROM AUTHOR]

Highlights • We find an inverse S-shape in stated subjective probabilities in a novel experiment. • Prelec's (1998) conditional invariant model provides the best fit. • We find a large degree of individual heterogeneity. Abstract We examine the nature of stated subjective probabilities in a complex, evolving context in which participants are not told what the actual probability is: we collect information on subjective expectations in a computerized car race game wherein participants must bet on a particular car but cannot influence the odds of winning once the race begins. In our setup, the actual probability of the good outcome (a win) can be determined based on computer simulations from any point in the process. We compare this actual probability to the subjective probability stated by participants at three different points in each of six races. In line with previous research in which participants have direct access to actual probabilities, we find that the inverse S-shaped curve relating subjective to actual probabilities is also evident in our far more complex situation, and that there is only a limited degree of learning through repeated play. We show that the model in the inverse S-shaped function family that provides the best fit to our data is Prelec's 1998 conditional invariant model. We also find that individuals who report a greater degree of ambiguity are more pessimistic and less responsive to actual changes in real probabilities. [ABSTRACT FROM AUTHOR]

Summary: Probability and chance are essential concepts, not just in statistics but in real life. We present an adaptable activity which investigates what we mean by bias, how we can identify bias, and how we can use it to our advantage! [ABSTRACT FROM AUTHOR]

The incidence of motor vehicle accidents increases sharply, especially with the students as the driver. Some causing factors of this accident are human error, problem on the vehicle, and environmental conditions. All these factors can be assumed to be the risk factor of accident occurrence on the highway either as a single or joint factor. To estimate probability of the traffic accidents on the rider. This research was an observational research-cross-sectional. The samples were 242 students as motorists in Surabaya used Simple Random Sampling. The data collection was done by interviews using a structured questionnaire. Students as a transition age group had an average motor driving experience of 5.41 years. An average age of 20.96 years and range 18-26 years. The gender carried different risks according to all incidents. The combined factors have probably that can be fatal to the safety of the rider (individual, vehicle, and environmental conditions). If the contribution of all factors equal to 85% then the chance of a traffic accident of 0.399 (39,9%). The need for knowledge about driving management on the highway. [ABSTRACT FROM AUTHOR]

Probability estimates can be given as ranges or uncertainty intervals, where often only one of the interval bounds (lower or upper) is specified. For instance, a climate forecast can describe La Niña as having 'more than 70% chance' or 'less than 90% chance' of occurring. In three experiments, we studied how research participants perceived climate-related forecasts expressed with lower-bound ('over X% chance') or upper-bound ('under Y% chance') probability statements. Results indicate that such single-bound statements give pragmatic information in addition to the numeric probabilities they convey. First, the studies show that these statements are directional, leading the listeners' attention in opposite directions. 'Over' statements guide attention towards the possible occurrence of the event and are explained by reasons for why it might happen, while 'under' statements direct attention to its possible non-occurrence and are more often explained by reasons for why the target event might not appear, corresponding to positive (it is possible) versus negative (it is uncertain) verbal probabilities. Second, boundaries were found to reveal the forecaster's beliefs and could be perceived as indicative of an increasing or a decreasing trend. Single-bound probability estimates are therefore not neutral communications of probability level but might 'leak' information about the speaker's expectations and about past and future developments of the forecast. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The past 12 years have seen significant steps forward in the science and practice of coastal flood analysis. This paper aims to recount and critically assess these advances, while helping identify next steps for the field. This paper then focuses on a key problem, connecting the probabilistic characterization of flood hazards to their physical mechanisms. Our investigation into the effects of natural structure on the probabilities of storm surges shows that several different types of spatial-, temporal-, and process-related organizations affect key assumptions made in many of the methods used to estimate these probabilities. Following a brief introduction to general historical methods, we analyze the two joint probability methods used in most tropical cyclone hazard and risk studies today: the surface response function and Bayesian quadrature. A major difference between these two methods is that the response function creates continuous surfaces, which can be interpolated or extrapolated on a fine scale if necessary, and the Bayesian quadrature optimizes a set of probability masses, which cannot be directly interpolated or extrapolated. Several examples are given here showing significant impacts related to natural structure that should not be neglected in hazard and risk assessment for tropical cyclones including: (1) differences between omnidirectional sampling and directional-dependent sampling of storms in near coastal areas; (2) the impact of surge probability discontinuities on the treatment of epistemic uncertainty; (3) the ability to reduce aleatory uncertainty when sampling over larger spatial domains; and (4) the need to quantify trade-offs between aleatory and epistemic uncertainties in long-term stochastic sampling. [ABSTRACT FROM AUTHOR]

Probabilistic Risk Assessment (PRA) has proven to be an invaluable tool for evaluating risks in complex engineered systems. However, there is increasing concern that PRA may not be adequate in situations with little underlying knowledge to support probabilistic representation of uncertainties. As analysts and policy makers turn their attention to deeply uncertain hazards such as climate change, a number of alternatives to traditional PRA have been proposed. This paper systematically compares three diverse approaches for risk analysis under deep uncertainty (qualitative uncertainty factors, probability bounds, and robust decision making) in terms of their representation of uncertain quantities, analytical output, and implications for risk management. A simple example problem is used to highlight differences in the way that each method relates to the traditional risk assessment process and fundamental issues associated with risk assessment and description. We find that the implications for decision making are not necessarily consistent between approaches, and that differences in the representation of uncertain quantities and analytical output suggest contexts in which each method may be most appropriate. Finally, each methodology demonstrates how risk assessment can inform decision making in deeply uncertain contexts, informing more effective responses to risk problems characterized by deep uncertainty. [ABSTRACT FROM AUTHOR]

We studied the effects of probabilistic cues, i.e., of information of limited certainty, in the context of an action task (GL: grip-lift) and of a perceptual task (WP: weight perception). Normal subjects (n = 22) saw four different probabilistic visual cues, each of which announced the likely weight of an object. In the GL task, the object was grasped and lifted with a pinch grip, and the peak force rates indicated that the grip and load forces were scaled predictively according to the probabilistic information. The WP task provided the expected heaviness related to each probabilistic cue; the participants gradually adjusted the object's weight until its heaviness matched the expected weight for a given cue. Subjects were randomly assigned to two groups: one started with the GL task and the other one with the WP task. The four different probabilistic cues influenced weight adjustments in the WP task and peak force rates in the GL task in a similar manner. The interpretation and utilization of the probabilistic information was critically influenced by the initial task. Participants who started with the WP task classified the four probabilistic cues into four distinct categories and applied these categories to the subsequent GL task. On the other side, participants who started with the GL task applied three distinct categories to the four cues and retained this classification in the following WP task. The initial strategy, once established, determined the way how the probabilistic information was interpreted and implemented. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study is to analyze the data obtained from a randomized trial on the prevention of influenza by gargling with green tea, which gave nonsignificant results based on frequentist approaches, by using Bayesian approaches. Methods: The posterior proportion, with 95% credible interval (CrI), of influenza in each group was calculated. The Bayesian index θ is the probability that a hypothesis is true. In this case, θ is the probability that the hypothesis that green tea gargling reduced influenza compared with water gargling is true. Univariate and multivariate logistic regression analyses were also performed by using the Markov chain Monte Carlo method. Results: The full analysis set included 747 participants. During the study period, influenza occurred in 44 participants (5.9%). The difference between the two independent binominal proportions was −0.019 (95% CrI, −0.054 to 0.015; θ = 0.87). The partial regression coefficients in the univariate analysis were −0.35 (95% CrI, −1.00 to 0.24) with use of a uniform prior and −0.34 (95% CrI, −0.96 to 0.27) with use of a Jeffreys prior. In the multivariate analysis, the values were −0.37 (95% CrI, −0.96 to 0.30) and −0.36 (95% CrI, −1.03 to 0.21), respectively. Conclusions: The difference between the two independent binominal proportions was less than 0, and θ was greater than 0.85. Therefore, green tea gargling may slightly reduce influenza compared with water gargling. This analysis suggests that green tea gargling can be an additional preventive measure for use with other pharmaceutical and nonpharmaceutical measures and indicates the need for additional studies to confirm the effect of green tea gargling. [ABSTRACT FROM AUTHOR]

Each organization has among its multiple secondary endpoints subordinated to a central objective that one of avoiding the contingencies. The direct procurement is carried out on the market in SEAP (Electronic System of Public Procurement), and a performing management in a public institution has as sub-base and risk management. The risks may be investigated by econometric simulation, which is calculated by the use of calculus of probability and the sample for determining the relevance of these probabilities. [ABSTRACT FROM AUTHOR]

We propose a forward-looking method to estimate the path for the federal funds target rate. We utilize six-month out probabilities of inflationary and disinflationary pressures, along with a labor market index, to estimate the fed funds rate. We further suggest that due to the changing nature of economies and impending risks to the economic outlook, a time-varying method (consistent with the nature of risks) would help decision makers to improve effective decision making. Our econometric results suggest disinflation (or disinflationary pressure), not inflationary pressure, best explains fed funds rate movements from the 1990s forward. Based on June 2016 data, there is a 55 percent chance that the inflation rate would stay below 1.5 percent during the next six months. The recent higher disinflationary pressure probability may be one reason the FOMC has repeatedly lowered its path for the fed funds rate. Unfortunately, the low-inflation zombie is real. [ABSTRACT FROM AUTHOR]

By means of the examples of classical and Bohmian quantum mechanics, we illustrate the well-known ideas of Boltzmann as to how one gets from laws defined for the universe as a whole the dynamical relations describing the evolution of subsystems. We explain how probabilities enter into this process, what quantum and classical probabilities have in common and where exactly their difference lies. [ABSTRACT FROM AUTHOR]

In Rational Econometric Man, Edward Nell and Karim Errouaki present a welcome and timely case for the view that econometrics and econometric model-building may not be the magic tools to solve all empirical questions despite what many seem to have thought they were in the 1960s. Here I examine some possible problems with econometric models that have to do with their usually taking the form of equilibrium models. Some of these problems were recognized by Trygve Haavelmo decades ago. And as Aris Spanos has recently discussed, the problems are often the result of what we say in our textbooks. Some problems have to do with what we mean by econometric parameters and others with how we use probabilities. [ABSTRACT FROM AUTHOR]

Aim To provide a mechanistic and probabilistic framework for defining the species pool based on species-specific probabilities of dispersal, environmental suitability and biotic interactions within a specific temporal extent, and to show how probabilistic species pools can help disentangle the geographical structure of different community assembly processes. Innovation Probabilistic species pools provide an improved species pool definition based on probabilities in conjunction with the associated species list, which explicitly recognize the indeterminate nature of species pool membership for a given focal unit of interest and better capture real-world complexity. Probabilistic species pools provide a quantitative assessment of how dispersal, environmental or biotic factors influence estimates of species pool composition and size for a given temporal extent. Conclusions Based on one simulated and two empirical examples we demonstrate that probabilistic species pools allow us to disentangle the geographical variation in dispersal, environmental and biotic assembly processes for species assemblages in focal units. We also show that probabilistic species pools are fully compatible with traditional definitions of species pools and are applicable over a wide range of spatial and temporal extents. Additionally they are robust to missing data and provide a quantified and transparent approach to estimating the size and composition of species pools in a mechanistic way, providing a valuable tool for studies from community ecology to macroecology. [ABSTRACT FROM AUTHOR]

This paper examines marginal-risk behavior in a decision-theoretic setting that is sufficiently general to accommodate any decision-making model representable by a certainty equivalent. The analysis shows that risk aversion in its usual sense is a special case of marginal-risk aversion associated with mean-preserving changes in gambles. Thus, marginal-risk behavior and risk behavior are not inherently different. Rather, they manifest similar behavior evaluated at different gambles. The paradox of marginal-risk-loving risk averters arises from mixing definitions of an "increase in risk". [ABSTRACT FROM AUTHOR]

Animals can shape their timed behaviors based on experienced probabilistic relations in a nearly optimal fashion. On the other hand, it is not clear if they adopt these timed decisions by making computations based on previously learnt task parameters (time intervals, locations, and probabilities) or if they gradually develop their decisions based on trial and error. To address this question, we tested mice in the timed-switching task, which required them to anticipate when (after a short or long delay) and at which of the two delay locations a reward would be presented. The probability of short trials differed between test groups in two experiments. Critically, we first trained mice on relevant task parameters by signaling the active trial with a discriminative stimulus and delivered the corresponding reward after the associated delay without any response requirement (without inducing switching behavior). During the test phase, both options were presented simultaneously to characterize the emergence and temporal characteristics of the switching behavior. Mice exhibited timed-switching behavior starting from the first few test trials, and their performance remained stable throughout testing in the majority of the conditions. Furthermore, as the probability of the short trial increased, mice waited longer before switching from the short to long location (experiment 1). These behavioral adjustments were in directions predicted by reward maximization. These results suggest that rather than gradually adjusting their time-dependent choice behavior, mice abruptly adopted temporal decision strategies by directly integrating their previous knowledge of task parameters into their timed behavior, supporting the model-based representational account of temporal risk assessment. [ABSTRACT FROM AUTHOR]

Bayes Rule specifies how probabilities over parameters should be updated given any kind of information. But in some cases, the kind of information provided by both simulation and physical experiments is information on how certain output parameters may change when other input parameters are changed. There are three different approaches to this problem, one of which leads to the Garbage-In/Garbage-Out Paradox, the second of which (Bayesian synthesis) violates the Borel Paradox, and the third of which (Bayesian melding) is a supra-Bayesian heuristic. This paper shows how to derive a fully Bayesian formula which avoids the Garbage-In/Garbage-Out and Borel Paradoxes. We also compare a Laplacian approximation of this formula with Bayesian synthesis and Bayesian melding and find that the Bayesian formula sometimes coincides with the Bayesian melding solution. [ABSTRACT FROM AUTHOR]

Probabilistic theories have been claimed to constitute a new paradigm for the psychology of reasoning. A key assumption of these theories is captured by what they call the Equation , the hypothesis that the meaning of the conditional is probabilistic in nature and that the probability of If p then q is the conditional probability, in such a way that P( if p then q ) = P( q | p ). Using the probabilistic truth-table task in which participants are required to evaluate the probability of If p then q sentences, the present study explored the pervasiveness of the Equation through ages (from early adolescence to adulthood), types of conditionals (basic, causal, and inducements) and contents. The results reveal that the Equation is a late developmental achievement only endorsed by a narrow majority of educated adults for certain types of conditionals depending on the content they involve. Age-related changes in evaluating the probability of all the conditionals studied closely mirror the development of truth-value judgements observed in previous studies with traditional truth-table tasks. We argue that our modified mental model theory can account for this development, and hence for the findings related with the probability task, which do not consequently support the probabilistic approach of human reasoning over alternative theories. [ABSTRACT FROM AUTHOR]

This paper considers the modelling of extreme-capability working platforms that are operated in periodic cycles, each cycle having a predefined number of operations that affect the working surfaces. A novel hypothesis is introduced about the platform-degrading effects that cause an equivalent decrease in the successful operations after repeated cycles. Deterministic modelling, based on the basic equations of Lanchester and Dinner, is generalized here to include coupling between parameters. The newly developed mathematical model of performance degradation is in good agreement with both experimental measurements and numerical simulations. It is assumed that the new variables and their correlations link the Gaussian distribution and the observed performances of the testing platforms. Relative probability dispersions of affected surfaces are derived, as a new indirect referencing figure of merit, to describe simulations and compare them to experimental test data. The model proves a hypothesis that the degrading effects are a function of the platform capacity, frequency of operations and the number of available cycles. Degradation effects are taken into account through an equivalent decrease of effective operation capacities, reflected on the properties of the affected operating surfaces. The obtained estimations of degradation could be used in the planning of platform capacity as well as in the selection of real affected surfaces in various machining systems and for a wide range of different materials. [ABSTRACT FROM AUTHOR]

Thibaud et al. ( Methods in Ecology and Evolution 2014) present a framework for simulating species and evaluating the relative effects of factors affecting the predictions from species distribution models (SDMs). They demonstrate their approach by generating presence-absence data sets for different simulated species and analysing them using four modelling methods: three presence-absence methods and Maxent, which is a presence-background modelling tool. One of their results is striking: that their use of Maxent performs well in estimating occupancy probabilities and even outperforms the other methods on small sample sizes. This result is of concern to us, because it suggests that Maxent directly offers a useful alternative for modelling presence-absence data, which may prompt widespread adoption of this use of Maxent. In this paper, we explore why this would be a mistake., We draw on the theory underlying how the Maxent model operates and on simulations to discover: (i) why Maxent appears to fare as well as it does in their evaluation and (ii) why the best-suited presence-absence method for data analysis (the generating model; a GLM) does not perform as well as we would expect., We demonstrate that (i) the good performance observed for Maxent is largely a coincidence; the simulated species match well the arbitrary default parameter that Maxent applies to map its relative output into a 0-1 scale, but errors are much larger for other species we simulate; (ii) the performance of the GLM is poorer than expected because Thibaud et al. do not use model selection and fit a model that is too complex for the amount of data available., Maxent is a presence-background method and only provides estimates of relative suitability regardless of how the background sample is specified. When presence-absence data are available, one can transform Maxent's relative estimates into estimates of occupancy probability, and we provide methods to do so. However, this requires the user to post-process Maxent's output. Proper PA methods such as GLMs can perform well under small sample sizes, provided care is taken during modelling to avoid overfitting. We demonstrate an effective method using regularisation with the R package glmnet. [ABSTRACT FROM AUTHOR]

Background: Inferential statistical tests that approximate measurement are called acceptance procedures. The procedure includes type 1 error, falsely rejecting the null hypothesis, and type 2 error, failing to reject the null hypothesis when the alternative should be supported. This approach involves repeated sampling from a distribution with established parameters such that the probabilities of these errors can be ascertained. With low error probabilities the procedure has the potential to approximate measurement. How close this procedure approximates measurement was examined. Findings: A Monte Carlo procedure set the type 1 error at p = 0.05 and the type 2 error at either p = 0.20 or p = 0.10 for effect size values of d = 0.2, 0.5, and 0.8. The resultant values are approximately 15 and 6.25 % larger than the effect sizes entered into the analysis depending on a type 2 error rate of p < 0.20, or p < 0.10 respectively. Conclusions: Acceptance procedures approximate values wherein a decision could be made. In a health district a deviation at a particular level could signal a change in health. The approximations could be reasonable in some circumstances, but if more accurate measures are desired a deviation could be reduced by the percentage appropriate for the power. The tradeoff for such a procedure is an increase in type 1 error rate and a decrease in type 2 errors. [ABSTRACT FROM AUTHOR]

In this paper, a critical discussion is made of the role of entailments in the so-called New Paradigm of psychology of reasoning based on Bayesian models of rationality (Elqayam & Over, 2013). It is argued that assessments of probabilistic coherence cannot stand on their own, but that they need to be integrated with empirical studies of intuitive entailment judgments. This need is motivated not just by the requirements of probability theory itself, but also by a need to enhance the interdisciplinary integration of the psychology of reasoning with formal semantics in linguistics. The constructive goal of the paper is to introduce a new experimental paradigm, called the Dialogical Entailment task, to supplement current trends in the psychology of reasoning towards investigating knowledge-rich, social reasoning under uncertainty (Oaksford & Chater, 2019). As a case study, this experimental paradigm is applied to reasoning with conditionals and negation operators (e.g. CEM and wide and narrow-scope negation). As part of the investigation, participants' entailment judgments are evaluated against their probability evaluations to assess participants' cross-task consistency over two experimental sessions. [ABSTRACT FROM AUTHOR]