Optimal Partitioning of a Data Set Based on the p-Median Model

Although the K-means algorithm for minimizing the within-cluster sums of squared deviations from cluster centroids is perhaps the most common method for applied cluster analyses, a variety of other criteria are available. The p-median model is an especially well-studied clustering problem that requires the selection of p objects to serve as cluster centers. The objective is to choose the cluster centers such that the sum of the Euclidean distances (or some other dissimilarity measure) of objects assigned to each center is minimized. Using 12 data sets from the literature, we demonstrate that a three-stage procedure consisting of a greedy heuristic, Lagrangian relaxation, and a branch-and-bound algorithm can produce globally optimal solutions for p-median problems of nontrivial size (several hundred objects, five or more variables, and up to 10 clusters). We also report the results of an application of the p-median model to an empirical data set from the telecommunications industry.     

Doxastic Voluntarism and the Function of Epistemic Evaluations

Control of our own beliefs is allegedly required for the truth of epistemic evaluations, such as “S ought to believe that p”, or “S ought to suspend judgment (and so refrain from any belief) whether p”. However, we cannot usually believe or refrain from believing at will. I agree with a number of recent authors in thinking that this apparent conflict is to be resolved by distinguishing reasons for believing that give evidence that p from reasons that make it desirable to believe that p whether or not p is true. I argue however that there is a different problem, one that becomes clearer in light of this solution to the first problem. Someone’s approval of our beliefs is at least often a non-evidential reason to believe, and as such cannot change our beliefs. Ought judgments aim to change the world. But ‘ought to believe’ judgments can’t do that by changing the belief, if they don’t give evidence. So I argue that we should instead regard epistemic ought judgments as aimed mainly at influencing assertions that express the belief and other actions based on the belief, in accord with recent philosophical claims that we have epistemic norms for assertion and action.     

Some Results on Mean Square Error for Factor Score Prediction

For the confirmatory factor model a series of inequalities is given with respect to the mean square error (MSE) of three main factor score predictors. The eigenvalues of these MSE matrices are a monotonic function of the eigenvalues of the matrix Γ _p = Φ ^1/2 Λ _p ′Ψ _p ⁻¹ Λ _p Φ ^1/2. This matrix increases with the number of observable variables p. A necessary and sufficient condition for mean square convergence of predictors is divergence of the smallest eigenvalue of Γ _p or, equivalently, divergence of signal-to-noise (Schneeweiss & Mathes, 1995). The same condition is necessary and sufficient for convergence to zero of the positive definite MSE differences of factor predictors, convergence to zero of the distance between factor predictors, and convergence to the unit value of the relative efficiencies of predictors. Various illustrations and examples of the convergence are given as well as explicit recommendations on the problem of choosing between the three main factor score predictors. The author is obliged to Maarten Speekenbrink and Peter van Rijn for their assistance with plotting the figures. In addition, I am obliged to the referees for their stimulating remarks.     

Kant,the Third Antinomy and Transcendental Arguments

In this paper, I consider whether a reading of Kant's solution to the Third Antinomy can offer material for devising a new model of transcendental argument. The problem that this form of argument is meant to address is an antinomy between two apparently contradictory claims, q and ¬q, where we seem equally justified in holding both. The model has the following form: p; q is a necessary condition of p; the only justification we have for q is that it is a necessary condition of p; p is justified only in domain X (where X is a domain of objects of cognition); therefore, q is justified only in domain X. Because the argument shows that our justification for q is valid only in X, it also establishes that there is conceptual space to hold ¬q outside of X.     

Associations of Youth and Adulthood Body-Mass Index and Waist-Hip Ratio with Attachment Styles and Dimensions

The current cross-sectional study examined whether body-mass index (BMI) and waist-hip ratio are associated with adult attachment. Participants were 1,570 men and women participating in Cardiovascular Risk in Young Finns study. BMI was measured in youth and in adulthood and waist-hip ratio in adulthood. A single measure of attachment style was conducted when participants were aged 24–39 years. In age and sex adjusted models, youth BMI (Beta = .066, p = .008), adulthood BMI (Beta = .069, p = .007) and waist-hip ratio (Beta = .082, p = .016) were associated with fearful attachment. The associations remained significant when education and relationship status were adjusted for. Age adjusted association between adulthood waist-hip ratio and preoccupied attachment was found in men (Beta = .132, p = .002). The association was not essentially changed by additionally adjusting for education and relationship status, and including fearful attachment in the model. Furthermore, associations for attachment dimensions were also found. These results suggest that in addition to previously reported negative effects of higher BMI on physical health, higher BMI might have negative associations with psychological functioning as well. Furthermore, our results imply that physical appearance might be associated with attachment style in adulthood.     

Advice for fallibilists: put knowledge to work

We begin by asking what fallibilism about knowledge is, distinguishing several conceptions of fallibilism and giving reason to accept what we call strong epistemic fallibilism, the view that one can know that something is the case even if there remains an epistemic chance, for one, that it is not the case. The task of the paper, then, concerns how best to defend this sort of fallibilism from the objection that it is “mad,” that it licenses absurd claims such as “I know that p but there’s a chance that not p” and “p but it there’s a chance that not p.” We argue that the best defense of fallibilism against this objection—a “pragmatist” defense—makes the following claims. First, while knowledge that p is compatible with an epistemic chance that not-p, it is compatible only with an insignificant such chance. Second, the insignificance of the chance that not-p is plausibly understood in terms of the irrelevance of that chance to p’s serving as a ‘justifier’, for action as well as belief. In other words, if you know that p, then any chance for you that not p doesn’t stand in the way of p’s being properly put to work as a basis for action and belief.

Pragmatic encroachment,stakes, and religious knowledge

It is commonly held that epistemic standards for S’s knowledge that p are affected by practical considerations, such as what is at stake in decisions that are guided by that p. I defend a particular view as to why this is, that is referred to as “pragmatic encroachment.” I then discuss a “new argument against miracles” that uses stakes considerations in order to explore the conditions under which stakes affect the level of epistemic support that is required for knowledge. Finally, I generalize my results to include other religiously significant propositions such as “God exists” and “God does not exist.”     

Happiness as Stable Extraversion: Internal Consistency Reliability and Construct Validity of the Oxford Happiness Questionnaire Among Undergraduate Students

The Oxford Happiness Questionnaire (OHQ) was developed by Hills and Argyle (2002) to provide a more accessible equivalent measure of the Oxford Happiness Inventory (OHI). The aim of the present study was to examine the internal consistency reliability, and construct validity of this new instrument alongside the Eysenckian dimensional model of personality. The Oxford Happiness Questionnaire was completed by a sample of 131 undergraduate students together with the abbreviated form of the Revised Eysenck Personality Questionnaire. The data demonstrated good internal consistency reliability (alpha = .92) and good construct validity in terms of positive association with extraversion (r = .38 p < .001) and negative association with neuroticism (r = −.57 p < .001). The kind of happiness measured by the OHQ is clearly associated with stable extraversion.     

A practical solution to the pervasive problems of<Emphasis Type="Italic">p</Emphasis> values

In the field of psychology, the practice ofp value null-hypothesis testing is as widespread as ever. Despite this popularity, or perhaps because of it, most psychologists are not aware of the statistical peculiarities of thep value procedure. In particular,p values are based on data that were never observed, and these hypothetical data are themselves influenced by subjective intentions. Moreover,p values do not quantify statistical evidence. This article reviews thesep value problems and illustrates each problem with concrete examples. The three problems are familiar to statisticians but may be new to psychologists. A practical solution to thesep value problems is to adopt a model selection perspective and use the Bayesian information criterion (BIC) for statistical inference (Raftery, 1995). The BIC provides an approximation to a Bayesian hypothesis test, does not require the specification of priors, and can be easily calculated from SPSS output.     

Perceptions of Familial Risk in those Seeking a Genetic Risk Assessment for Alzheimer’s Disease

Perceived risk is a complex concept that influences the genetic counseling process and can affect client coping and behavior. Although the association between family history and risk perception is well recognized in the literature, no studies have explored this relationship specifically in those seeking genetic susceptibility testing for a common chronic condition. REVEAL is a randomized trial assessing the impact of APOE disclosure and genetic risk assessment for Alzheimer’s disease (AD). Using baseline REVEAL data, we hypothesized that there would be a significant association between the degree of AD family history and risk perception of AD, and that this relationship would be stronger in those who believed that genetics is a very important AD risk factor. In our sample of 293 participants, we found that a higher self-perceived risk of AD was associated with strength of family history of AD (p < 0.001), belief in genetics as an important AD risk factor (p < 0.001), being female (p < 0.001) and being Caucasian (p = 0.02). These results are the first to demonstrate the association between family history and risk perception in persons volunteering for genetic susceptibility testing for a common complex disease.     

The Responsible Subject in the Global Age

The first thesis of this article is that the concept of responsibility takes on an unprecedented meaning in the twentieth century resulting from the emergence of a new dimension of the other: to be responsible comes to mean not just to account for oneself in relation to the other, but also to take the other into account, to take care of the other—what I call responsibility towards (the other). The main reason for this change consists in the emergence of global risks and the necessity, as underlined by Hans Jonas, to be responsible for the destiny of the world and future generations. The problem, as explored in the article’s second thesis, is that this implies the existence of a subject who is capable of responsibility. Jonas’s insights on this point are insufficient, since he only recognizes duty as the fundament for his ethics of responsibility and thus neglects the problem of motivation. This is a particularly crucial problem today as we are witnessing the presence of a pathological subject, characterized by a split in his faculties (between doing and imagining, knowing and feeling). To underline this fact, this article makes use of Günther Anders’s reflections, which provide a psycho-anthropological analysis of the subject, showing his pathologies and the necessity, from a moral perspective, to overcome his scission. Finally, this author suggests, as the article’s third thesis, that this overcoming is the necessary fundament for the perception of risk, which in turn reinstates the subject’s perception of his own vulnerability. Responsibility thus finds a motivation, which is neither altruistic nor duty-centred, in the awareness of our own vulnerability and the bond with the destiny of humankind as a whole.     

The CHIC Model: A Global Model for Coupled Binary Data

Often problems result in the collection of coupled data, which consist of different N-way N-mode data blocks that have one or more modes in common. To reveal the structure underlying such data, an integrated modeling strategy, with a single set of parameters for the common mode(s), that is estimated based on the information in all data blocks, may be most appropriate. Such a strategy implies a global model, consisting of different N-way N-mode submodels, and a global loss function that is a (weighted) sum of the partial loss functions associated with the different submodels. In this paper, such a global model for an integrated analysis of a three-way three-mode binary data array and a two-way two-mode binary data matrix that have one mode in common is presented. A simulated annealing algorithm to estimate the model parameters is described and evaluated in a simulation study. An application of the model to real psychological data is discussed. T. Wilderjans is a Research Assistant of the Fund for Scientific Research—Flanders (Belgium). The research reported in this paper was partially supported by the Research Council of K.U. Leuven (GOA/2005/04). We are grateful to Kristof Vansteelandt for providing us with an interesting data set. We also thank three anonymous reviewers for their useful comments.     

An Evaluation of the Relation Between Distress Tolerance and Posttraumatic Stress within a Trauma-Exposed Sample

The present investigation examined the incremental associations between distress tolerance, or the perceived capacity to tolerate emotional distress, and global posttraumatic stress symptom severity as well as symptom cluster severity, beyond the variance accounted for by number of trauma exposure types and negative affectivity. The sample consisted of 140 adults (72 women; M _age = 25.9, SD = 11.1) who endorsed exposure to traumatic life events, as defined by posttraumatic stress disorder diagnostic criterion A (American Psychiatric Association 2000). Participants did not meet diagnostic criteria for current axis I psychopathology. Distress tolerance demonstrated significant incremental associations with global posttraumatic stress symptom severity (p < .01) as well as re-experiencing (p < .05), avoidance (p = .05), and hyperarousal (p < .001) symptom cluster severity. Given the cross-sectional study design, causation cannot be inferred. Theoretical implications and future directions for better understanding associations between distress tolerance and posttraumatic stress are discussed.     

The Generalized DINA Model Framework

The G-DINA (generalized deterministic inputs, noisy “and” gate) model is a generalization of the DINA model with more relaxed assumptions. In its saturated form, the G-DINA model is equivalent to other general models for cognitive diagnosis based on alternative link functions. When appropriate constraints are applied, several commonly used cognitive diagnosis models (CDMs) can be shown to be special cases of the general models. In addition to model formulation, the G-DINA model as a general CDM framework includes a component for item-by-item model estimation based on design and weight matrices, and a component for item-by-item model comparison based on the Wald test. The paper illustrates the estimation and application of the G-DINA model as a framework using real and simulated data. It concludes by discussing several potential implications of and relevant issues concerning the proposed framework.     

Deflationism and the Dependence of Truth on Reality

A common objection against deflationism is that it cannot account for the fact that truth depends on reality. Consider the question ‘On what does the truth of the proposition that snow is white depend?’ An obvious answer is that it depends on whether snow is white. Now, consider what answer, if any, a deflationist can offer. The problem is as follows. A typical deflationary analysis of truth consists of biconditionals of the form ‘The proposition that p is true iff p’. Such biconditionals tell us nothing about what the truth of the proposition that p might depend on. Therefore, it seems that a typical deflationist cannot give an answer. Since we know that an answer is available, this throws doubt over the adequacy of deflationism as an account of truth. Articulated here is a defence of deflationism against this objection. It is argued that although biconditionals of the sort mentioned do not explicitly state a dependency between truth and reality, they nevertheless convey one. The reason is that, given the context in which a deflationist invokes the biconditionals, such a dependency is implicated. A potential problem with this defence is that it leaves the deflationist still unable to give an account of what it is for truth to depend on reality. One might think that a deflationist can offer such an account by appealing to truthmaker theory but, it is argued below, truthmaker theory is unavailable to a deflationist. Instead, the deflationist should question the assumption that an account is available.     

Gricean Communication and Transmission of Thoughts

Gricean communication is communication between utterers and their audiences, where the utterer means something and the audience understands what is meant. The weak transmission idea is that, whenever such communication takes place, there is something which is transmitted from utterer to audience; the strong transmission idea adds that what is transmitted is nothing else than what is communicated. We try to salvage these ideas from a seemingly forceful attack by Wayne Davis. Davis attaches too much significance to the surface structure of sentences of the type ‘S communicates the belief (desire …) that p to A’ by assuming that the communicated entity is denoted by the grammatical object following ‘communicates’. On our proposal, what is communicated in all Gricean cases is a thought. And since S communicates the thought that p to A only if S means that p and A understands what S means, the thought that p will be transmitted from S to A.     

Fearful asymmetry: Kierkegaard’s search for the direction of time

The ancient problem of whether our asymmetrical attitudes towards time are justified (or normatively required) remains a live one in contemporary philosophy. Drawing on themes in the work of McTaggart, Parfit, and Heidegger, I argue that this problem is also a key concern of Kierkegaard’s Either/Or (1843). Part I of Either/Or presents the “aesthete” as living a temporally volatilized form of life, devoid of temporal location, sequence and direction. Like Parfit’s character “Timeless,” these aesthetes are indifferent to the direction of time and seemingly do not experience McTaggart’s “A-Series” mode of temporality. The “ethical” conception of time that Judge William offers in Part II contains an attempt to normativize the direction of time, by re-orienting the aesthete towards an awareness of time’s finitude. However, the form of life Judge William articulates gives time sequentiality but not necessarily the robust directionality necessary to justify (and make normative) our asymmetrical attitudes to time. Hence while Either/Or raises this problem it remains unanswered until The Concept of Anxiety (1844). Only with the eschatological understanding of time developed in The Concept of Anxiety does Kierkegaard answer the question of why directional and asymmetrical conative and affective attitudes towards time are normative.     

Dream Skepticism and the Conditionality Problem

Recently, Ernest Sosa (2007) has proposed two novel solutions to the problem of dream skepticism. In the present paper, I argue that Sosa’s first solution falls prey to what I will refer to as the conditionality problem, i.e., the problem of only establishing a conditional—in this case, “if x, then I am awake,” x being a placeholder for a condition incompatible with dreaming—in a context where it also needs to be established that we can know that the antecedent holds, and as such can infer the consequent, i.e., “I am awake.” Sosa’s second solution, in terms of so-called reflective knowledge, is shown to land him in the dilemma of either facing yet another conditionality problem, or violating an internalist constraint that he explicitly grants the skeptic with respect to what kind of factors can be legitimately invoked in our account of how we may know the relevant antecedent. For these reasons, I conclude that Sosa has not solved the problem of dream skepticism.     

Gricean Belief Change

One of the standard principles of rationality guiding traditional accounts of belief change is the principle of minimal change: a reasoner's belief corpus should be modified in a minimal fashion when assimilating new information. This rationality principle has stood belief change in good stead. However, it does not deal properly with all belief change scenarios. We introduce a novel account of belief change motivated by one of Grice's maxims of conversational implicature: the reasoner's belief corpus is modified in a minimal fashion to assimilate exactly the new information. In this form of belief change, when the reasoner revises by new information p ∨ q their belief corpus is modified so that p∨q is believed but stronger propositions like p∧q are not, no matter what beliefs are in the reasoner's initial corpus. We term this conservative belief change since the revised belief corpus is a conservative extension of the original belief corpus given the new information.     

In the Eye of the Beholder: Alcohol Use and Perceptions Among Student-Patrons of ‘Joints’ in Three Nigerian University Communities

Alcohol use and its associated problems among university students have attracted empirical investigation by researchers and scholars. While many of these studies have reported a very high level of alcohol consumption and highlighted the various problems this portends, alcohol-related perceptions of this vulnerable population, which could be germane to intervention aimed at curtailing the problem, have remained largely under-researched. This cross-sectional survey examined the use and perceptions of alcohol by student-patrons (n = 1,705) of beer parlours or ‘joints’ in three university communities in Southwest Nigeria. Respondents were interviewed using AUDIT, a socio-demographic prototype and an open-ended section on alcohol-related perceptions of the students. Findings indicated that overall, 72% of the respondents perceived that alcohol is good for socializing, 68% perceived that alcohol is good in the aspect of stress reduction, 58% believed that alcohol consumption is indicative of maturity, 36% perceived that alcohol enhances their sexual performance while 39% perceived that alcohol serves to enhance alertness/concentration. Results also showed that gender (β = −. 23; p < .05), paternal alcohol use (β = .36; p < .01), parental socio-economic status (β = .33; p < .01), and residential status of university of respondents (β = .21; p < .05) significantly predicted alcohol use. The study concluded that perceptions about alcohol are very germane to understanding students’ alcohol use and should be reckoned with in designing intervention programmes. The need to adopt a ‘client-centered’ approach to the problem of student drinking behaviour was emphasized.