A cautionary note on using internal cross validation to select the number of clusters

A highly popular method for examining the stability of a data clustering is to split the data into two parts, cluster the observations in Part A, assign the objects in Part B to their nearest centroid in Part A, and then independently cluster the Part B objects. One then examines how close the two partitions are (say, by the Rand measure). Another proposal is to split the data into k parts, and see how their centroids cluster. By means of synthetic data analyses, we demonstrate that these approaches fail to identify the appropriate number of clusters, particularly as sample size becomes large and the variables exhibit higher correlations.The authors express their thanks to the Sol C. Snider Entrepreneurial Center, Wharton School, for support of this project.     

Gender Differences in Memory Perspectives: Evidence for Self-Objectification in Women

This study tests Fredrickson and Roberts' (1997)assertion that cultural practices of sexuallyobjectifying women's bodies socialize women tointernalize an observer's perspective on their physicalselves. Autobiographical memories can contain imagesfrom two perspectives: the original, first personperspective (field images) and that of an outsideobserver (observer images) (Nigro and Neisser, 1983). We collected autobiographical memories for eventsin general and for specific, potentially objectifyingsituations from a predominantly European-American sampleof 138 female and 104 male students at a private university. Results demonstrated that femaleparticipants reported more observer imagery than maleparticipants both for memories in general and formemories of certain situations wherein women are likely to be sexually objectified. Women's and men'semotional responses to these situations were alsodifferent, with women reporting more negative affect,including shame and anxiety, and less positiveaffect.     

Dating Relationships and the Demand/Withdraw Pattern of Communication

This study examines whether afemale-demand/male-withdraw pattern occurs in datingrelationships and whether this response increases duringdiscussions of difficult topics. One hundred and eightindividuals (women = 60, men = 48) currently in a datingrelationship completed the Communication PatternsQuestionnaire, Short Form (CPQSF) regarding either adifficult or nondifficult discussion. The racialcomposition of the undergraduate student population at thetime the study was conducted was 68.8% Caucasian, 8.9%Hispanic, 8.9% International, 6.0% African American,5.6% Asian American, and 1.8% Native American (data on socioeconomic status were unavailable).Results show that dating couples do employ apredominantly female-demand/male-withdraw pattern, whichincreases in response to difficult discussions. However, this study also found that many dating couplesemployed male-demand/female-withdraw or equaldemand/withdraw patterns. Post hoc tests also showedthat couples exhibiting eitherfemale-demand/male-withdraw or male-demand/female-withdraw patterns weremore ingrained in specific negative behavior patterns,employed more demand/withdraw behaviors, and exhibitedless positive behaviors than couples with an equal demand/withdraw pattern.     

Encouraging counsellor reflection

The evolution of an 'attributes checklist' tool for assisting counsellor development is described. The attributes relate to characteristics of case-notes that indicate evidence of counsellor reflection and consideration of the counselling process. The checklist was initially tested among a sample of 19 counsellors employed by an organisational EAP and was subsequently refined. The final checklist tool was found to be both usable and useful in differentiating 'process' from 'content' notes. The purpose of the checklist tool is not to enable quantitative assessment of counsellor notes, but rather to facilitate counsellor development within a professional supervisory relationship. The findings of the study are discussed, and suggestions for future research in this area are made.     

Suicide and Attachment: Fear of Abandonment and Isolation from a Developmental Perspective

Suicide risk has been found to be associated with particular attachment styles. The purpose of this paper is to discuss suicide risk in terms of family dynamics, and the development of attachments with others. Theories of suicide and development, including those by Freud, Erikson, Bowlby, Richman, and Kaplan, and their clinical implications, are discussed. Literary works by Kafka and Plath are also discussed in the context of suicide and attachment. It is concluded that families characterized by excessive enmeshment and/or detachment often produce an atmosphere of isolation and intolerance which increases suicide risk.     

Should We Teach Patriotism?

This article examines a particular debate between Eamonn Callan and William Galston concerning the need for a civic education which counters the divisive pull of pluralism by uniting the citizenry in patriotic allegiance to a single national identity.The article offers a preliminary understanding of nationalism and patriotism before setting out the terms of the debate. It then critically evaluates the central idea of Callan that one might be under an obligation morally to improve one's own patriotic inheritance, pointing to the ineliminable tension between the valuation of one's own patria by its own terms and a detached critical reason.It concludes by suggesting that we are, in advance of our education, members of a particular patria and that any education must be particularistic. Finally, the danger is noted of presuming that, in each case, there is a single, determinate national tradition.     

Agency And Consciousness

In Intentionality and other works, John Searle establishes himself as a leading defender of the view that consciousness of what one is doing is always a component of one’s action. In this paper I focus on problems with Searle’s view to establish that there are actions in which the agent is not at all aware of what she is doing. I argue that any theory that misses this sort of action keeps us from important insights into autonomy, self-knowledge and responsibility. This revised version was published online in August 2006 with corrections to the Cover Date.     

Amount of reward has opposite effects on the discounting of delayed and probabilistic outcomes

Previous research has shown that the value of large future rewards is discounted less steeply than is the value of small future rewards. These experiments extended this line of research to probabilistic rewards. Two experiments replicated the standard findings for delayed rewards but demonstrated that amount has an opposite effect on the discounting of probabilistic rewards. That is, large probabilistic amounts were discounted at the same or higher rates than small amounts. Although amount had opposite effects on the discounting of delayed and probabilistic rewards, nevertheless, the same form of mathematical function accurately described discounting of both types of reward. The findings suggest that fundamentally similar, but not identical, processes are involved in decision making regarding delayed and probabilistic rewards. The implications of these findings for impulsivity and self-control are discussed.     

Reducing indices of unhappiness among individuals with profound multiple disabilities during therapeutic exercise routines.

A program was developed to reduce indices of unhappiness that accompanied therapeutic exercise routines among people with profound multiple disabilities. Indices of unhappiness were recorded, using an observation system that had been validated through previous research involving happiness-related variables, while support personnel conducted exercises with 3 participants. A multicomponent program was then implemented that involved presenting highly preferred stimuli before, during, and after each exercise session. Results indicated that the program was accompanied by reduced indices of unhappiness for each participant relative to the traditional method of conducting the exercises, although changes in the preferred stimuli used with 1 participant were required before consistent reductions occurred. Results are discussed regarding the importance of reducing unhappiness indices as a means of enhancing aspects of the daily quality of life for people with profound multiple disabilities. Areas for future research are also discussed, focusing on expanding the unhappiness-reduction procedures to other routine events that may occasion indices of unhappiness.     

Intersensory conflict between vision and touch: the response modality dominates when precise, attention-riveting judgments are required

In four experiments, reducing lenses were used to minify vision and generate intersensory size conflicts between vision and touch. Subjects made size judgments, using either visual matching or haptic matching. In visual matching, the subjects chose from a set of visible squares that progressively increased in size. In haptic matching, the subjects selected matches from an array of tangible wooden squares. In Experiment 1, it was found that neither sense dominated when subjects exposed to an intersensory discrepancy made their size estimates by using either visual matching or haptic matching. Size judgments were nearly indentical for conflict subjects making visual or haptic matches. Thus, matching modality did not matter in Experiment 1. In Experiment 2, it was found that subjects were influenced by the sight of their hands, which led to increases in the magnitude of their size judgments. Sight of the hands produced more accurate judgments, with subjects being better able to compensate for the illusory effects of the reducing lens. In two additional experiments, it was found that when more precise judgments were required and subjects had to generate their own size estimates, the response modality dominated. Thus, vision dominated in Experiment 3, where size judgments derived from viewing a metric ruler, whereas touch dominated in Experiment 4, where subjects made size estimates with a pincers posture of their hands. It is suggested that matching procedures are inadequate for assessing intersensory dominance relations. These results qualify the position (Hershberger & Misceo, 1996) that the modality of size estimates influences the resolution of intersensory conflicts. Only when required to self-generate more precise judgments did subjects rely on one sense, either vision or touch. Thus, task and attentional requirements influence dominance relations, and vision does not invariably prevail over touch.