Testing the efficiency of Markov chain Monte Carlo with People using facial affect categories

Exploring how people represent natural categories is a key step toward developing a better understanding of how people learn, form memories, and make decisions. Much research on categorization has focused on artificial categories that are created in the laboratory, since studying natural categories defined on high-dimensional stimuli such as images is methodologically challenging. Recent work has produced methods for identifying these representations from observed behavior, such as reverse correlation (RC). We compare RC against an alternative method for inferring the structure of natural categories called Markov chain Monte Carlo with People (MCMCP). Based on an algorithm used in computer science and statistics, MCMCP provides a way to sample from the set of stimuli associated with a natural category. We apply MCMCP and RC to the problem of recovering natural categories that correspond to two kinds of facial affect (happy and sad) from realistic images of faces. Our results show that MCMCP requires fewer trials to obtain a higher quality estimate of people's mental representations of these two categories.     

AFFIRMATIONS AFTER GOD: FRIEDRICH NIETZSCHE AND RICHARD DAWKINS ON ATHEISM

Abstract. In this essay, I compare the atheism of Friedrich Nietzsche with that of Richard Dawkins. My purpose is to describe certain differences in their respective atheisms with the intent of showing that Nietzsche's atheism contains a richer and fuller affirmation of human life. In Dawkins’s presentation of the value of life without God, there is a naïve optimism that purports that human beings, educated in science and purged of religion, will find lives of easy peace and comfortable wonder. Part of my argument is that this optimism regarding the power of objective science is subject to Nietzsche's criticism of Socrates and what he calls the “theoretical man.” As such, it fails in terms of providing a true affirmation of life in the godless world.     

Investigating the Impact of Noneffortful Responses on Individual-Level Scores: Can the Effort-Moderated IRT Model Serve as a Solution?

Suboptimal effort is a major threat to valid score-based inferences. While the effects of such behavior have been frequently examined in the context of mean group comparisons, minimal research has considered its effects on individual score use (e.g., identifying students for remediation). Focusing on the latter context, this study addressed two related questions via simulation and applied analyses. First, we investigated how much including noneffortful responses in scoring using a three-parameter logistic (3PL) model affects person parameter recovery and classification accuracy for noneffortful responders. Second, we explored whether improvements in these individual-level inferences were observed when employing the Effort Moderated IRT (EM-IRT) model under conditions in which its assumptions were met and violated. Results demonstrated that including 10% noneffortful responses in scoring led to average bias in ability estimates and misclassification rates by as much as 0.15 SDs and 7%, respectively. These results were mitigated when employing the EM-IRT model, particularly when model assumptions were met. However, once model assumptions were violated, the EM-IRT model’s performance deteriorated, though still outperforming the 3PL model. Thus, findings from this study show that (a) including noneffortful responses when using individual scores can lead to potential unfounded inferences and potential score misuse, and (b) the negative impact that noneffortful responding has on person ability estimates and classification accuracy can be mitigated by employing the EM-IRT model, particularly when its assumptions are met.     

Discussions

Summary  In their paper, ‘When are thought experiments poor ones?’ (Peijnenburg and David Atkinson, 2003, Journal of General Philosophy of Science 34, 305-322.), Jeanne Peijnenburg and David Atkinson argue that most, if not all, philosophical thought experiments are “poor” ones with “disastrous consequences” and that they share the property of being poor with some (but not all) scientific thought experiments. Noting that unlike philosophy, the sciences have the resources to avoid the disastrous consequences, Peijnenburg and Atkinson come to the conclusion that the use of thought experiments in science is in general more successful than in philosophy and that instead of concocting more “recherché” thought experiments, philosophy should try to be more empirical. In this comment I will argue that Peijnenburg’s and Atkinson’s view on thought experiments is based on a misleading characterization of both, the dialectical situation in philosophy as well as the history of physics. By giving an adequate account of what the discussion in contemporary philosophy is about, we will arrive at a considerably different evaluation of philosophical thought experiments.

For I am convinced that we now find ourselves at an altogether decisive turning point in philosophy, and that we are objectively justified in considering that an end has come to the fruitless conflict of systems. We are already at the present time, in my opinion, in possession of methods which make any such conflict in principle unnecessary. What is now required is their resolute application. (Schlick, ‘The Turning Point in Philosophy’, 1930/1959, p. 54).

     

Understanding Psychopathology: Melding Behavior Genetics, Personality, and Quantitative Psychology to Develop an Empirically Based Model

ABSTRACT— Research on psychopathology is at a historical crossroads. New technologies offer the promise of lasting advances in our understanding of the causes of human psychological suffering. Making the best use of these technologies, however, requires an empirically accurate model of psychopathology. Much current research is framed by the model of psychopathology portrayed in current versions of the Diagnostic and Statistical Manual of Mental Disorders ( DSM ; American Psychiatric Association, 2000 ). Although the modern DSM s have been fundamental in advancing psychopathology research, recent research also challenges some assumptions made in the DSM —for example, the assumption that all forms of psychopathology are well conceived of as discrete categories. Psychological science has a critical role to play in working through the implications of this research and the challenges it presents. In particular, behavior-genetic, personality, and quantitative-psychological research perspectives can be melded to inform the development of an empirically based model of psychopathology that would constitute an evolution of the DSM .     

基于人格特征的即时通讯软件用户分类模型

根据即时通讯(instantmessaging,IM)软件工具使用行为的差异将用户划分为两类,使用“大五人格问卷”获取了该两类IM用户的人格特征测量数据。统计分析结果表明,上述两类用户在“适应性”和“社交性”因子上的得分存在显著差异,而在“开放性”、“利他性”和“道德感”三个因子上的得分差异不显著。据此,以用户在“适应性”与“社交性”因子上的得分为输入和用户的分类类别为输出,构建了IM用户基于人格特征的BP神经网络分类模型。对模型的拟合度检验表明,该模型可利用人格测量数据对IM用户进行有效分类。     

SCIENCE AND THE FORTUNES OF NATURAL THEOLOGY: SOME HISTORICAL PERSPECTIVES

Abstract. The object is to examine strategies commonly used to heighten a sense of the sacred in nature. It is argued that moves designed to reinforce a concept of Providence have been the very ones to release new opportunities for secular readings. Several case studies reveal this fluidity across a sacred-secular divide. The irony whereby sacred readings of nature would graduate into the secular is also shown to operate in reverse as anti-providentialist strategies invited their own refutation. The analysis is used to support the claim that the sciences have put fewer constraints on religious belief than is generally assumed.     

A processing model for the analysis of one-way arguments in discourse

This paper describes a computational model for analyzing arguments in discourse. In particular, the model describes processes necessary for interpreting one uninterrupted argument from a speaker. The resulting output is a representation for the underlying claim and evidence relations between propositions of the argument. For our processing model we present: (i) a characterization of coherent orderings of propositions, used to limit search for interpretation of each new proposition (ii) a working definition of the evidence relation, used to recognize connections between propositions (iii) a theory of the function and use of clue words — special words and phrases indicating the structure of the argument — then used in the analysis to control search for interpretation and verification of evidence relations.     

Locke and Whately on the Argumentum ad Hominem

This is an exploration of what Locke and Whately said about the Argumentatum ad Hominem, especially in the context of what they said about the other ad arguments, and with a view to ascertaining whether what they said lends support to the understanding of this argument implicit in Johnstone's thesis that all valid philosophical arguments are ad hominem. It is concluded that this support is forthcoming insofar as Locke and Whately had in mind an argument concerned with principles.The essay ends with a brief reformulation of Johnstone's generalization regarding philosophical arguments.