The research is focused on the role of two related key concepts, namely variables and data, in the impact evaluations of public projects. A difficult task of the evaluators and researchers is to select the appropriate variables to ensure the best model of reality and satisfy the evaluation methods' needs. Therefore, the paper aims to look at the current knowledge and discuss how variables and data could be best used to connect the evaluation models, the particularities of the intervention with (...) the potential of the advanced quantitative assessment methods. The results emphasise that evaluations operate with data with different levels of granularity, as required by the intervention logic. Structuring data in clusters and categories, performing evaluability assessments are useful in assessing data quality and limitations and improving them. In line with the existing literature, we demonstrate that data accessibility is a key constraint and imposes adjustment of the desired evaluation model to a feasible one. While Big Data and Open Data systems significantly improved data quality in evaluations in recent years, blockchain, as a ledger technology with default features related to decentralisation and security, is expected to bring large benefits to evaluation. For evaluators and policymakers, blockchain potential is an area of further research looking for additional advantages that could enhance the use of quantitative methods. (shrink)

The statistical evidence for the detrimental effect of exposure to low levels of lead on the cognitive capacities of children has been debated for several decades. In this paper I describe how two techniques from artificial intelligence and statistics help make the statistical evidence for the accepted epidemiological conclusion seem decisive. The first is a variable-selection routine in TETRAD III for finding causes, and the second a Bayesian estimation of the parameter reflecting the causal influence of Actual Lead Exposure, (...) a latent variable, on the measured IQ score of middle class suburban children. (shrink)

this requirement for adaptations. Emergent characters are always potential adaptations. Not all selection processes produce adaptations, however. The key issue, in delineating a selection process, is the relationship between a character and fitness. The emergent character approach is more restrictive than alternative schemas that delineate selection..

Traditional portfolio selection models mainly obtain the optimized portfolio ratio by focusing on the prices of financial products. However, investors’ multiple preferences and risk appetites are also significant factors that should be taken into account. In consideration of these two factors simultaneously, we propose a double-hierarchy model in this paper. Specifically, the first hierarchy quantifies investors’ risk appetite based on a historical simulation method and probabilistic preference theory. This hierarchy can be utilized to describe investors’ variable risk appetites and (...) ensure the obtained investment ratios meet investors’ immediate risk requirements. Then, using the cross-efficiency evaluation principle, the optimal investment ratios can be derived by fusing investors’ multiple preferences and risk appetites in the second hierarchy. Lastly, an illustrative example about evaluating the 10 largest capitalized stocks on the Shenzhen Stock Exchange is given to verify the feasibility and effectiveness of our newly proposed model. We make the theoretical contribution to improve the traditional portfolio selection model, especially considering investors’ subjective preferences and risk appetite. Moreover, the proposed model can be practical for assisting investors with their investment strategies in real life. (shrink)

Volume 20, Issue 2, February 2020, Page 33-35.

Whenever the use of non-experimental data for discovering causal relations or predicting the outcomes of experiments or interventions is contemplated, two difficulties are routinely faced. One is the problem of latent variables, or confounders: factors influencing two or more measured variables may not themselves have been measured or recorded. The other is the problem of sample selection bias: values of the variables or features under study may themselves influence whether a unit is included in the data sample.

if and only if for every W in V, W is independent of the set of all its non-descendants conditional on the set of its parents. One natural question that arises with respect to DAGs is when two DAGs are “statistically equivalent”. One interesting sense of “statistical equivalence” is “d-separation equivalence” (explained in more detail below.) In the case of DAGs, d-separation equivalence is also corresponds to a variety of other natural senses of statistical equivalence (such as representing the same (...) set of distributions). Theorems characterizing d-separation equivalence for directed acyclic graphs and that can be used as the basis for polynomial time algorithms for checking d-separation equivalence were provided by Verma and Pearl (1990), and Frydenberg (1990). The question we will examine is how to extend these results to cases where a DAG may have latent (unmeasured) variables or selection bias (i.e. some of the variables in the DAG have been conditioned on.) D-separation equivalence is of interest in part because there are algorithms for constructing DAGs with latent variables and selection bias that are based on observed conditional independence relations. For this class of algorithms, it is impossible to determine which of two d-separation equivalent causal structures generated a given probability distribution, given only the set of conditional independence and dependence relations true of the observed distribution. We will describe a polynomial (in the number of vertices) time algorithm for determining when two DAGs which may have latent variables or selection bias are d-separation equivalent. (shrink)

Learning equivalence classes of acyclic models with latent and selection variables from multiple datasets with overlapping variables is discussed. The problem of inferring the presence of latent variables, their relation to the observables, and the relation among themselves, is considered. A different approach for identifying causal structures, one that results in much simpler equivalence classes, is provided. It is found that the computational cost is much higher than the procedure implemented, but if datasets are individually of modest dimensionality, it (...) might be doable in practice. From the point of view of search algorithms for optimizing structure, much of the machinery of combinatorial optimization could optimize the penalized composite likelihood score by enforcing constraints such that the independence models over different subsets of variables agree on the overlapping sets. (shrink)

This study examines the potential effects of unethically perceived advertising executionson consumer responses to the ad. The study found that the unethical perceptions of the advertisement shown significantly and negatively affected all advertising response variables examined in the study.

This work gives an extended presentation of the treatment of variable-binding operators adumbrated in [3:1993d]. Illustrative examples include elementary languages with quantifiers and lambda-equipped categorial languages. Some remarks are also offered to illustrate the philosophical import of the resulting picture. Particularly, a certain conception of logic emerges from the account: the view that logics are true theories in the model-theoretic sense, i.e. the result of selecting a certain class of models as the only “admissible” interpretation structures (for a given language).

Decision-making is a complex action requiring efficient information processing. Specifically, in movement in which performance efficiency depends on reaction time, e.g., open-loop controlled movements, these processes may play a crucial role. Information processing includes three distinct stages, stimulus identification, response selection, and response programming. Mainly, response selection may play a substantial contribution to the reaction time and appropriate decision making. The duration of this stage depends on the number of possible choices an individual has to “screen” to make (...) a proper decision. Given that reaction time is crucial in many sports, the possibilities of reducing it through practice are very tempting. The information processing and its relationship to the manner an individual is practicing are discussed. Especially the variability of practice issues will be explored. In variable practice conditions, an individual has to react to one or more stimuli and has to produce one of the many variations of the same movement or different movements they learned. One has to identify a stimulus appropriately and has to select a response optimally, i.e., choosing from as few choices as possible to reduce the reaction time. On the other hand, in constant practice conditions, an individual can be exposed to one or many stimuli. Still, there is only one variation of the movement that can be executed in the presence of a learned stimulus. Based on the information processing theory and the results of the research focusing on variability of practice, I discuss how the practice conditions may affect reaction time and, as a result, the decision-making process. I conceptually frame the possible implications of practice conditions on decision making related to information processing. In this review, a possible mechanism and relationship between practice conditions and decision-making are presented. Future research directions are presented. (shrink)

RESUMEN Se desarrolló una investigación descriptiva transversal, con un enfoque cuantitativo, en la que la muestra fue seleccionada de manera intencional pura, no probabilística, según criterios establecidos por los autores del estudio. Quedó constituida por las variables del Sistema Comprehensivo Rorschach pertenecientes a 120 protocolos de sujetos con trastornos depresivos, de ellos 82 presentaron depresión moderada, y 38 depresión severa. Se aplicaron los siguientes métodos empíricos: entrevista, observación, Autoescala de Zung y Conde, y el Psicodiagnóstico de Rorschach. Los estadígrafos que (...) se utilizaron fueron el Test de Kolmogorov- Smirnov, el Test de Comparación de Proporciones y la prueba de Mann-Whitney. Como principales resultados se obtuvo que las variables del Sistema Comprehensivo Rorschach, que establecieron diferencias estadísticas altamente significativas entre los grupos de sujetos fueron: Lambda alta, Proporción afectiva baja, total de respuestas, las respuestas globales, Suma Ponderada de respuestas con el determinante color cromático y la Experiencia accesible. ABSTRACT A transverse descriptive investigation was developed, with a quantitative approach, in that the sample was selected in a pure intentional way, not probabilistic, according to criteria established by the authors of the study. It was constituted for the variables of the Rorschach Comprehensive System belonging to 120 protocols of individuals with depressive disorders, of them 82 presented moderate depression, and 38 severe depression. The following empirical methods were applied: interview, observation, Auto-scale of Zung and Conde, and Psycho-diagnosis of Rorschach. The statisticians used were the Test of Kolmogorov - Smirnov, the Test of Comparison of Proportions and the Mann-Whitney test. As main results, it was obtained that the variables of the Rorschach Comprehensive System, which established highly significant statistical differences between the groups of individuals were: tall Lambda, low affective proportion, whole of answers, the global answers, exaggerated sum of answers with the determinant chromatic color and the accessible experience. (shrink)

This paper develops twenty hypotheses concerning the relationships among selected individual differences variables (locus of control, delay of gratification, gender, and race) and five different ethical beliefs. The results of a study of collegians provide support for seventeen out of twenty research hypotheses. As predicted, locus of control, delay of gratification, and race are related to ethical beliefs. Also as predicted, gender is not related to ethical beliefs.

This article considers the evolutionary roots of education in the hominin lineage drawing on the variability selection hypothesis. The variability selection hypothesis emphasizes adaptation to a variable environment and flexible behavior. However, the archaeological record indicates that there are some structuring factors including learned technical skill and knowledge, trends in the progressive development of technology, and the contextual influence on the adaptive advantage conferred by learning versus trial and error. Thus, the flexibility of hominin behavior includes (...) both the ability to develop novel responses to changing conditions and to structure behavior within constraints. It is argued that negotiating between the capacity for flexibility and for behavior based on learned structures is fundamental to the practice of education. (shrink)

The Bell/CHSH inequalities of quantum physics are identical with the inequalities derived in mathematical psychology for the problem of selective influences in cases involving two binary experimental factors and two binary random variables recorded in response to them. The following points are made regarding cognitive science applications: (1) compliance of data with these inequalities is informative only if the data satisfy the requirement known as marginal selectivity; (2) both violations of marginal selectivity and violations of the Bell/CHSH inequalities are interpretable (...) as indicating that at least one of the two responses is influenced by both experimental factors. (shrink)

The enormous scale of the available information and products on the Internet has necessitated the development of algorithms that intermediate between options and human users. These algorithms attempt to provide the user with relevant information. In doing so, the algorithms may incur potential negative consequences stemming from the need to select items about which it is uncertain to obtain information about users versus the need to select items about which it is certain to secure high ratings. This tension is an (...) instance of the exploration–exploitation trade‐off in the context of recommender systems. Because humans are in this interaction loop, the long‐term trade‐off behavior depends on human variability. Our goal is to characterize the trade‐off behavior as a function of human variability fundamental to such human–algorithm interaction. To tackle the characterization, we first introduce a unifying model that smoothly transitions between active learning and recommending relevant information. The unifying model gives us access to a continuum of algorithms along the exploration–exploitation trade‐off. We then present two experiments to measure the trade‐off behavior under two very different levels of human variability. The experimental results inform a thorough simulation study in which we modeled and varied human variability systematically over a wide rage. The main result is that exploration–exploitation trade‐off grows in severity as human variability increases, but there exists a regime of low variability where algorithms balanced in exploration and exploitation can largely overcome the trade‐off. (shrink)

This book explores issues at the core of modern linguistics and cognitive science. Why are all languages similar in some ways and in others utterly different? Why do languages change and change variably? How did the human capacity for language evolve, and how far did it do so as an innate ability? Simon Kirby looks at these questions from a broad perspective, arguing that they can be studied together. The author begins by examining how far the universal properties of language (...) may be explained by examining the way it is used, and how far by the way it is structured. He then considers what insights may be gained by combining functional and formal approaches. In doing so he develops a way of treating language as an adaptive system, in which its communicative and formal roles are both crucial and complementary. In order to test the effectiveness of competing theories and explanations, Simon Kirby develops computational models to show what universals emerge given a particular theory of language use or acquisition. He presents here both the methodology and the results. Function, Selection, and Innateness is important for its argument, its methodology, and its conclusions. It is a powerful demonstration of the value of looking at language as an adaptive system and goes to the heart of current debates on the evolution and nature of language. (shrink)

The practices of economists increase experimental reproducibility relative to those of selected psychologists but should not be universally adopted. Procedures criticized by Hertwig and Ortmann as producing variable data are valuable, instead, for generating questions. The procedure of choice should depend on the theoretical goal: measure a known factor or learn what factors are important and need to be measured.

Sexual selection traditionally involves male-male competition and female choice, but in some species, including humans, sexual selection can also involve female-female competition and male choice. The degree to which one aspect of sexual selection or another is manifest in human populations will be influenced by a host of social and ecological variables, including the operational sex ratio. These variables are discussed in connection with the relative contribution of sexual selection and the division of labor to the (...) evolution of human sex differences. (shrink)

A gene is considered essential when its loss of function results in a deleterious phenotype, hugely reducing the organism's viability or fitness. However, the link between the essentiality of a gene and its degree of polymorphism is unclear. In this review, we show that there is a place for a certain degree of variability, even for essential genes. We first study the role of infectious diseases in the prevalence of genetic disorders among humans: balancing selection has selected harmful (...) variants due to the selective pressure of pathogens because the heterozygous carrier can resist them. Then we show that the environment can induce adaptation of species by rapidly evolving genes. We also study the role of positive selection on speciation, particularly upon genes of the immune, reproductive and nervous systems. Finally, we highlight the role of regulatory sequences in changes in morphology between species and adaptation to the environment within species. (shrink)

Many have argued that there is no reason why natural selection should cause directional increases in measures such as body size or complexity across evolutionary history as a whole. In this paper I argue that this conclusion does not hold for selection for adaptations to environmental variability, and that, given the inevitability of environmental variability, trends in adaptations to variability are an expected feature of evolution by natural selection. As a concrete instance of this (...) causal structure, I outline how this may be applied to a trend in phenotypic plasticity. (shrink)

Under the putative influence of dietary selection pressure, the subcellular distribution of alanine:glyoxylate aminotransferase 1 (AGT) has changed on many occasions during the evolution of mammals. Depending on the particular species, AGT can be found either in peroxisomes or mitochondria, or in both peroxisomes and mitochondria. This variable localization depends on the differential expression of N‐terminal mitochondrial and C‐terminal peroxisomal targeting sequences by the use of alternative transcription and translation initiation sites. AGT is peroxisomal in most humans, but it (...) is mistargeted to the mitochondria in a subset of patients suffering from the rare herediatry disease primary hyperoxaluria type 1. Mistargeting is due to the unlikely combination of a normally occurring polymorphism that generates a functionally weak mitochondrial targeting sequence and a disease‐specific mutation which, in combination with the polymorphism, inhibits AGT dimerization. The mechanisms by which AGT can be targeted differentially to peroxisomes and/or mitochondria highlight the different molecular requirements for protein import into these two organelles. (shrink)

IntroductionDeep brain stimulation has become a standard treatment option for select patients with Parkinson’s disease. The selection process and surgical procedures employed have, to date, not been standardized.MethodsA comprehensive 58-question web-based survey was developed with a focus on DBS referral practices and peri-operative management. The survey was distributed to the Parkinson’s Foundation Centers of Excellence, members of the International Parkinson’s Disease and Movement Disorders Society, and the Parkinson Study Group between December 2015 and May 2016.ResultsThere were 207 individual respondents (...) drawn from 59 countries and 6 continents, of whom 64% received formal training in DBS. Thirteen percent of centers reported that DBS could proceed despite a confidence level of < 50% for PD diagnosis. A case-based approach to DBS candidacy was applied in 51.3% of centers without a cut-off for levodopa-responsiveness. Surprisingly, 33% of centers regularly used imaging for diagnostic confirmation of idiopathic PD. Thirty-one percent of centers reported that neuropsychological evaluation did not affect DBS target selection. Approximately half of the respondents reported determination of DBS candidacy based on a multidisciplinary committee evaluation and 1/3rd reported that a committee was used for target selection. Eight percent of respondents felt that psychosocial factors should not impact DBS candidacy nor site selection. Involvement of allied health professionals in the preoperative process was sparse. There was high variability in preoperative education about DBS outcome expectations. Approximately half of the respondents did not utilize a “default brain target,” though STN was used more commonly than GPi. Specific DBS procedure techniques applied, as well as follow-up timelines, were highly variable.ConclusionResults revealed high variability on the best approaches for DBS candidate selection, brain target selection, procedure type, and postoperative practices. Cognitive and mood assessments were underutilized. There was low reliance on multidisciplinary teams or psychosocial factors to impact the decision-making process. There were small but significant differences in practice across global regions, especially regarding multidisciplinary teams. The wide variability of responses across multiple facets of DBS care highlights the need for prospective studies to inform evidence-based guidelines. (shrink)

The causal Bayes net framework specifies a set of axioms for causal discovery. This article explores the set of causal variables that function as relata in these axioms. Spirtes showed how a causal system can be equivalently described by two different sets of variables that stand in a non-trivial translation-relation to each other, suggesting that there is no “correct” set of causal variables. I extend Spirtes’ result to the general framework of linear structural equation models and then explore to what (...) extent the possibility to intervene or a preference for simpler causal systems may help in selecting among sets of causal variables. (shrink)

Procedures for the selection of subjects for participation in randomized clinical trials--usually formalized as eligibility criteria in the study protocol--have both scientific and ethical implications. In this thesis, I undertake an examination of eligibility criteria at three stages in the genesis and dissemination of medical knowledge: clinical trial protocol, interpretation by investigators, and reporting of study results.In the first chapter, ethical issues in subject selection are reviewed and the main study questions are presented. In the second chapter, the (...) results of an examination of eligibility criteria in two sets of clinical trials, one sponsored by the NSABP, the other sponsored by POG, covering a twenty-year time span are presented. The POG trials had far fewer eligibility criteria than the NSABP studies, suggesting that large numbers of criteria may not be necessary for high quality research. In the third chapter, the impact of subjective eligibility criteria on enrollment and investigator uncertainty is explored. Subjective criteria were associated with more variable enrollment decisions and greater uncertainty. Such criteria represent a threat to the validity, conduct and interpretation of trials and, therefore, should only be included when carefully justified. The fourth chapter examines the accuracy of the reporting of eligibility criteria in sets of corresponding study protocol, methods paper, journal article, and Clinical Alert. Important information is lost at each step in the dissemination of study results. Unnecessary criteria ought to be dropped at a trial's inception; all other criteria must be reported faithfully. The fifth chapter attempts to provide a comprehensive philosophical account of just selection procedures for clinical research using the political philosophy of Michael Walzer. The sixth, and last, chapter, discusses explanatory and pragmatic approaches to clinical trial design, overlapping scientific and ethical concerns related to eligibility criteria, and questions for further study. (shrink)

This Article examines the influence of the Americans with Disabilities Act (ADA) on affective attitudes toward children with disabilities and on the incidence of disability-selective abortion. Applying regression analysis to U.S. natality data, we find that the birthrate of children with Down syndrome declined significantly in the years following the ADA's passage. Controlling for technological, demographic, and cultural variables suggests that the ADA may have encouraged prospective parents to prevent the existence of the very class of people the Act was (...) designed to protect. We explain this paradox by showing how specific ADA provisions could have given rise to demeaning media depictions and social conditions that reinforced negative understandings and expectations among prospective parents about what it means to have a child with a disability. We discuss implications for reproduction law and antidiscrimination policy. (shrink)

Skipper and Millstein analyze natural selection and mechanism, concluding that natural selection is not a mechanism in the sense of the new mechanistic philosophy. Barros disagrees and provides his own account of natural selection as a mechanism. This discussion identifies a missing piece of Barros's account, attempts to fill in that piece, and reconsiders the revised account. Two principal objections are developed: one, the account does not characterize natural selection; two, the account is not mechanistic. Extensive (...) and persistent variability causes both of these difficulties, so further attempts to describe natural selection as a mechanism are also unlikely to succeed. (shrink)

We present a general theory of series-parallel mental architectures with selectively influenced stochastically non-independent components. A mental architecture is a hypothetical network of processes aimed at performing a task, of which we only observe the overall time it takes under variable parameters of the task. It is usually assumed that the network contains several processes selectively influenced by different experimental factors, and then the question is asked as to how these processes are arranged within the network, e.g., whether they are (...) concurrent or sequential. One way of doing this is to consider the distribution functions for the overall processing time and compute certain linear combinations thereof (interaction contrasts). The theory of selective influences in psychology can be viewed as a special application of the interdisciplinary theory of (non)contextuality having its origins and main applications in quantum theory. In particular, lack of contextuality is equivalent to the existence of a “hidden” random entity of which all the random variables in play are functions. Consequently, for any given value of this common random entity, the processing times and their compositions (minima, maxima, or sums) become deterministic quantities. These quantities, in turn, can be treated as random variables with (shifted) Heaviside distribution functions, for which one can easily compute various linear combinations across different treatments, including interaction contrasts. This mathematical fact leads to a simple method, more general than the previously used ones, to investigate and characterize the interaction contrast for different types of series-parallel architectures. (shrink)

Few problems in the philosophy of evolutionary biology are more widely disseminated and discussed than the charge of Darwinian evolution being a tautology. The history is long and complex, and the issues are many, and despite the problem routinely being dismissed as an introductory-level issue, based on misunderstandings of evolution, it seems that few agree on what exactly these misunderstandings consist of. In this paper, I will try to comprehensively review the history and the issues. Then, I will try to (...) present the following “solution”, or, one might say, “dissolution”, of the problem, and consider the wider implications of formal, or schematic, explanations in science: yes, the principle of natural selection is a tautology, and so what? It is a promissory note for actual, physical, explanations in particular cases, and is none the worse for that. This is not a new argument, of course, but it does point up the importance of formal schematic models in science. (shrink)

In this commentary we make two rejoinders to Jung & Haier (J&H). First, we highlight the response selection component in tasks as a confounding variable that may explain the parieto-frontal involvement in studies of human intelligence. Second, we suggest that efficient response selection may be an integral part of the definition of intelligence.

Variability is prevalent in early language acquisition, but, whether it supports or hinders learning is unclear; while target variability has been shown to facilitate word learning, variability in competitor items has been shown to make the task harder. Here, we tested whether background variability could boost learning in a referent selection task. Two groups of 2-year-old children saw arrays of one novel and two known objects on a screen, and they heard a novel or known (...) label. Stimuli were identical across conditions, with the exception that in the constant color condition objects appeared on a uniform white background, and in the variable color condition backgrounds were different, uniform colors. At test, only children in the variable condition showed evidence of retaining label-object associations. These data support findings from the adult memory literature, which suggest that variability supports learning by decontextualizing representations. We argue that these data are consistent with dynamic systems accounts of learning in which low-level entropy adds sufficient noise to the developmental system to precipitate a change in behavior. (shrink)

A new etiological model is proposed for schizophrenia that combines variability‐enhancing nonspecific factors acting during development with more specific risk factors. This model is better suited than the current etiological models of schizophrenia, based on the risk factors paradigm, for predicting and/or explaining several important findings about schizophrenia: high co‐morbidity rates, low specificity of many risk factors, and persistence in the population of the associated genetic polymorphisms. Compared with similar models, e.g., de‐canalization, common psychopathology factor, sexual‐selection, or differential (...) sensitivity to the environment, this proposal is more general and integrative. Recently developed research methods have proven the existence of genetic and environmental factors that enhance developmental variability. Applying such methods to newly collected or already available data can allow for testing the hypotheses upon which this model is built. If validated, this model may change the understanding of the etiology of schizophrenia, the research models, and preventionbrk paradigms. (shrink)

In the 1940s, the ‘modern synthesis’ (MS) of Darwinism and genetics cast genetic mutation and recombination as the source of variability from which environmental events naturally select the fittest, such ‘natural selection’ constituting the cause of evolution. Recent biology increasingly challenges this view by casting genes as followers and awarding the leading role in the genesis of adaptations to the agency and plasticity of developing phenotypes—making natural selection a consequence of other causal processes. Both views of natural (...) selection claim to capture the core of Darwin’s arguments in On the Origin of Species. Today, historians largely concur with the MS’s reading of Origin as a book aimed to prove natural selection the cause (vera causa) of adaptive change. This paper finds the evidence for that conclusion wanting. I undertake to examine the context and meaning of all Darwin’s known uses of the phrase vera causa, documenting in particular Darwin’s resistance to the pressure to prove natural selection a vera causa in letters written early in 1860. His resistance underlines the logical dependence of natural selection, an unobservable phenomenon, on the causal processes producing the observable events captured by the laws of inheritance, variation, and the struggle for existence, established in Chapters 1–3 of Origin. (shrink)