An examination of indexes for determining the number of clusters in binary data sets

The problem of choosing the correct number of clusters is as old as cluster analysis itself. A number of authors have suggested various indexes to facilitate this crucial decision. One of the most extensive comparative studies of indexes was conducted by Milligan and Cooper (1985). The present piece of work pursues the same goal under different conditions. In contrast to Milligan and Cooper's work, the emphasis here is on high-dimensional empirical binary data. Binary artificial data sets are constructed to reflect features typically encountered in real-world data situations in the field of marketing research. The simulation includes 162 binary data sets that are clustered by two different algorithms and lead to recommendations on the number of clusters for each index under consideration. Index results are evaluated and their performance is compared and analyzed.Author names are listed in alphabetical order.This piece of research was supported by the Austrian Science Foundation (FWF) under grant SFB#010 (Adaptive Information Systems and Modeling in Economics and Management Science).The authors would like to thank the anonymous reviewers and especially the associate editor for their helpful comments and suggestions.     

Group choice: the ideal free distribution of human social behavior

Group choice refers to the distribution of group members between two choice alternatives over time. The ideal free distribution (IFD), an optimal foraging model from behavioral ecology, predicts that the ratio of foragers at two resource sites should equal the ratio of obtained resources, a prediction that is formally analogous to the matching law of individual choice, except that group choice is a social phenomenon. Two experiments investigated the usefulness of IFD analyses of human group choice and individual-based explanations that might account for the group-level events. Instead of nonhuman animals foraging at two sites for resources, a group of humans chose blue and red cards to receive points that could earn cash prizes. The groups chose blue and red cards in ratios in positive relation to the ratios of points associated with the cards. When group choice ratios and point ratios were plotted on logarithmic coordinates and fitted with regression lines, the slopes (i.e., sensitivity measures) approached 1.0 but tended to fall short of it (i.e., undermatching), with little bias and little unaccounted for variance. These experiments demonstrate that an IFD analysis of group choice is possible and useful, and suggest that group choice may be explained by the individual members' tendency to optimize reinforcement.     

Patterns and evolution of moral behaviour: moral dynamics in everyday life

Recent research on moral dynamics (the processes and phenomena – collective or individual – by which moral behaviour and moral attitudes emerge, evolve, spread, erode or disappear) shows that an individual's ethical mind-set (i.e. outcome-based vs. rule-based) moderates the impact of an initial ethical or unethical act on the likelihood of behaving ethically on a subsequent occasion. More specifically, an outcome-based mind-set facilitates Moral Balancing (behaving ethically or unethically decreases the likelihood of engaging in the same type of behaviour again later), whereas a rule-based mind-set facilitates Moral Consistency (engaging in an ethical or unethical behaviour increases the likelihood of engaging in the same type of behaviour later on). The objective was to look at the evolution of moral choice across a series of scenarios, that is, to explore if these moral patterns (Balancing vs. Consistency) are maintained over time. The results of three studies showed that Moral Balancing is not maintained over time. On the other hand, Moral Consistency could be maintained over time, if the mind-set was reinforced before making a new moral judgment (but not otherwise).     

The emotional relations of children's participation rights in diverse social and spatial contexts: Advancing the field

Children's participation rights, enshrined in the UN Convention on the Rights of the Child (1989), have been a popular area of research, policy and practice for decades. Despite a great deal of interest and activity, participation rights have posed a particular challenge to implement. In response, researchers have consistently called for more in-depth and nuanced analyses of the way participatory rights are actually lived and experienced by children and young people, within the complexity of interdependent relationships. However, there has been surprisingly little focus on the emotional relations of children's participation rights. The analytical links between emotions and participation rights are rarely the focus and, where emotions are discussed, they are rarely discussed as a central concern in their own right. This article provides a review of the field and identifies three ways in which making emotions a central concern can help to advance debates on children's participation rights: by helping to unsettle ‘traditional’ constructions of the child-adult binary, by increasing sensitivity to ethical and safeguarding issues, and by making visible and challenging intersectional power relations.     

Temperature dependence of nucleation rate in a binary solid solution

The influence of regression (partial dissolution) effects on the temperature dependence of nucleation rate in a binary solid solution has been studied theoretically. The results of the analysis are compared with the predictions of the simplest Volmer–Weber theory. Regression effects are shown to have a strong influence on the shape of the curve of nucleation rate versus temperature. The temperature T_M at which the maximum rate of nucleation occurs is found to be lowered, particularly for low interfacial energy (coherent precipitation) and high-mobility species (e.g. interstitial atoms).     

How different is a 3D‐printed replica from a conspecific in the eyes of a zebrafish?

Robotics is emerging as a promising tool for aiding research on animal behavior. The possibility of generating customizable, controllable, and standardized robotic stimuli has been demonstrated through a number of behavioral assays, involving vertebrates and invertebrates. However, the specific appraisal of the nature of robotic stimuli is currently lacking. Here, we attempt to evaluate this aspect in zebrafish, through a within‐subject design in which experimental subjects are faced with three experimental conditions. In the first test, we investigated sociability by measuring zebrafish response to a conspecific separated by a one‐way glass. In the second test, we studied zebrafish behavior in response to a 3D‐printed zebrafish replica actuated along realistic trajectories through a novel four‐degree‐of‐freedom robotic platform. Last, we investigated fear responses in a shelter‐seeking test. In agreement with our expectations, zebrafish exhibited an equivalent preference for live and robotic stimuli, and the degree of preference for the robotic replica correlated negatively with the individual propensity to seek shelter. The equivalent preference for the replica and conspecific suggests that the appraisal of the target stimuli is analogous. The preliminary evidence of a correlation between behavioral responses across tests points to the readability of robotics‐based approaches to investigate interindividual differences.     

Social cognitive influences on Mexican Americans’ career choices across Holland’s themes

This study examined several propositions of social cognitive career theory ( [Lent et al., 1994] and [Lent et al., 2000]) with a sample of 393 Mexican American college students. It was hypothesized that person input (i.e., age) and background contextual variables (i.e., Anglo orientation, Mexican orientation, familism, instrumentality, and expressivity) would predict career self-efficacy across Holland’s (1997) six RIASEC types. In addition, we examined the proposed relations between career self-efficacy, career interests, and career choice goal across the six RIASEC areas. Our results indicated that (a) Artistic, Social, Enterprising, and Conventional career models were similar across gender and university affiliation groups, (b) gender differences were found in the Realistic career model, (c) institutional affiliation differences were found in the Investigative career model, and (d) the models were a good fit to the data. Implications for future vocational research and career interventions are discussed.     

An Alternative Model of Political Reasoning

The primary instrument of dispute management in political liberalism is a form of political thinking and talking that tries to reconcile opposed positions with an impartial settlement based on fair arrangements and mutual respect, one that is careful to treat rival views equitably, and reasoned through from start to finish with open methods that lead to a public justification understandable to the disputants. But this model of reasoning is notoriously deficient in resolving disputes among radically different communities. A more effective form of political reasoning for these disputes that yet respects the background values of liberalism is found in the languages of state depicted in realist accounts of international relations. These languages avoid liberal appeals to be reasonable, reciprocity controlled by moral criteria, and the quest for common reasons. They represent a deliberative search for an accord that will meet the interests of the disputing parties as they define these interests and understand the settlements, and in this sense are welcome models to manage divisive issues in pluralist democracies. A complete version of political reasoning would contain both liberal and realpolitik models and a mechanism to adjudicate the appropriate uses of each model.I do not know how even to begin thanking my spring 2003 graduate seminar for the wonderful discussions that allowed me to refine my thinking on this research project. In different ways the following individual members of the seminar were helpful: Amanda Dipaolo, Dimitria Gatzia, Michael McFall, Michael McKeon, Roald Nashi, Paul Prescott, Joshua Vermette, Amy Widestrom, and the two regular auditors, Cyril Ghosh and Darrell Driver. I have also profited from numerous discussions with other graduate students, including, early in this project, Steven Benko and, more constantly, Ali Shomali. Faculty colleagues who have commented on the work and suggested literatures for me to read and references to track include James Bennett, Hans Schmidt, Peg Hermann, Elizabeth Cohen, Jim Watts, Jim Wiggins, David Miller and Thomas Green. I am particularly grateful to Everita Silina, a graduate student who has been a constant friend and invaluable research assistant for the past five years. The Miami International Relations Theory group provided a critical venue to try out portions of this paper at the University of Miami campus on April 23, 2004. I then presented a later version of the paper to a Philosophy Department colloquium at the University of Miami on April 22, 2005. The comments made by those who attended one or both of the sessions were very helpful. I am also grateful to Ken Baynes and Ned McClennen for allowing me to be an unlisted third instructor in their seminar on “law, economics and public reason” in the fall semester 2004 at Syracuse University, and for the opportunity to present some of this work at one of the seminar meetings. If anything demonstrates the importance of a good collective setting on intellectual work this seminar was one such demonstration.     

假想的道德两难情境下小学儿童对说谎或说真话的抉择

研究探讨了294名7、9、11岁的小学儿童在道德两难情境下对说谎或说真话的道德行为抉择。结果表明,在个人谎故事条件下,随着年龄的增长,儿童越来越倾向于选择说真话;在集体谎故事条件下,11岁儿童比7岁、9岁儿童更倾向于选择说谎。7岁儿童已具有初步的集体观念,随着年龄的增长,小学儿童的集体观念日趋稳定。随着年龄的增长,小学儿童更多地从诚实、为集体或为个人等多个方面来陈述说谎或说真话的理由。