A reformulation of the general Euclidean model for the external analysis of preference data

This paper discusses least squares methods for fitting a reformulation of the general Euclidean model for the external analysis of preference data. The reformulated subject weights refer to a common set of reference vectors for all subjects and hence are comparable across subjects. If the rotation of the stimulus space is fixed, the subject weight estimates in the model are uniquely determined. Weight estimates can be guaranteed nonnegative. While the reformulation is a metric model for single stimulus data, the paper briefly discusses extensions to nonmetric, pairwise, and logistic models. The reformulated model is less general than Carroll's earlier formulation.The author is grateful to Christopher J. Nachtsheim for his helpful suggestions.     

Advancing knowledge about delinquency and crime: The need for a coordinated program of longitudinal research

Past research on delinquency and crime has provided convincing data about correlates but not about causes, because it has been largely cross-sectional in design. Whereas cross-sectional research focuses on variations between subjects, longitudinal research can provide information about changes within subjects, which are more important for causes, prevention, and treatment. Many of the most important results in criminology have been obtained in longitudinal or experimental studies, and the major studies of these types are reviewed here. It is now desirable to combine the two methods in a new coordinated program of longitudinal studies including experimental interventions or quasi-experimental analyses. Such projects could study several overlapping cohorts, extend from birth to adulthood, have frequent data collection, and obtain data from a variety of sources about many different types of antisocial behavior.     

The Relevance of Systemic Thinking to Student Counselling

After outlining the predominant approaches which currently inform student counselling a case is made for adopting a developmental systemic paradigm, locating individual difficulties within the context of a family dilemma. The view is taken that family systems thinking and individual approaches can be complementary and that systemic work need not be restricted to formal family therapy and the technology this implies.     

A simulation-based tutorial system for exploring parallel distributed processing

This article presents a simulation-based tutorial system for exploring parallel distributed processing (PDP) models of information processing. The system consists of software and an accompanying handbook. The intent of the package is to make the ideas underlying PDP accessible and to disseminate some of the main simulation programs that we have developed. This article presents excerpts from the handbook that describe the approach taken, the organization of the handbook, and the software that comes with it. An example is given that illustrates the approach we have taken to teaching PDP, which involves presentation of relevant mathematical background, together with tutorial exercises that make use of the simulation programs.     

A high-gain,low-noise amplifier for EEG

This paper describes an amplifier for an electroencephalograph with gain of 1×10⁴ to 1×10⁶ and made entirely of commercially available IC components. The two-stage amplifier has a preamplifier stage with fixed gain of 1000, and a second stage with variable gain from 1 to 100. The final stage, an anti-aliasing filter, adds a gain of 10 to the signal. The circuit has high common mode rejection, low input bias current, very low noise characteristics, low offset voltages, and offset nulling capability built into the circuit.     

Earthquake Preparedness: Predictors in a Community Survey1

We measured the relationship between earthquake concern and preparation in a community with high seismic risk. Five samples of approximately 800 people were interviewed by telephone about their earthquake concern, but this study focuses on the last two samples in which respondents reported their preparatory behaviors. The findings were consistent in showing greater likelihood of concern for those who had experienced an earthquake, were female, younger, and non-Anglo and a greater likelihood of preparation for those who had more concern, were married, and had lived longer at their present address. In a nonrecursive causal model, no evidence was found for a reciprocal effect of preparation on concern. These results were discussed in terms of health belief models including the self-efficacy and “stages of change” perspectives. Implications were drawn for interventions to increase preparation in ready-to-change groups and compensate for the resistance of those less willing or able to prepare.     

Ratings of Orally Presented Verbal Expressions of Probability by a Heterogeneous Sample

Verbal expressions of probability are used in daily conversations, physician-physician and physician-patient communications, and questionnaire and interview responses. To assess the degree of agreement among English-speaking Australian adults in allocating numerical probabilities to these verbal expressions of probability, 966 interviewees provided estimates for 60 isolated expressions of probability and a sequence of seven items placed in a sequence. Means and median scores appeared to be consistent with common sense and with findings from other countries. Mirror-imaged terms were neither symmetrical nor equidistant, with the means and medians for the positive terms being closer to the mid-points of the scale than the means and medians of the negative terms. Items in a sequence of probability terms showed greater symmetry and less variability than isolated expressions. For most items, there was an unacceptably high level of within-subject and between-subject variability. Although subjects with higher levels of education and/ or mathematics education showed less variability, these factors accounted for very little of the variance. The greater variability in Australian results relative to those reported elsewhere was partly attributed to the use of interviews rather than questionnaires. There were no particular stems that yielded greater consistency. It was concluded that the use of these expressions leads to very imprecise communication.     

Declines in Major League Batting Performance as a Function of Game Pressure: A Drive Theory Analysis1

Zajonc's (1965) drive theory explanation argues that greater arousal tends to impair performance on difficult tasks. The hypothesis that arousal generated by “pressure situations” during major league baseball games would hinder batting performance—a difficult task—was tested by examining such performance during the 1989 season. Six “pressure situations” were identified, some occurring during the late innings of close games and others occurring throughout the game when there were two outs. Two measures of batting performance (batting average and slugging average) were employed. Results indicated broad support for the hypothesis. Reasons for this pattern are discussed, as are possible alternative explanations for these findings.     

An "Epidemic" Model of Adolescent Cigarette Smoking

The prevalence of regular smoking increases rapidly during adolescence. We applied modeling methods from the study of epidemic infectious disease to smoking behavior. Our "epidemic" models dealt with the process of transition among four states: nonsmoker (susceptible), trier (exposed), regular smoker (infected), and ex-smoker (recovered). The best fitting model was one in which the transition from nonsmoker to trier was a social contagion process where nonsmokers contacted either triers or regular smokers. All other transitions were treated as constant rate processes in which a constant proportion of eligible individuals made the transition in a given year. The recursive equation model embodying these assumptions was able to predict accurately the proportion of adolescents in each state in Grades 6–11. Our results support a "stage" model of smoking, suggesting that different psychological and physiological processes are involved in the initiation of smoking than in developing a habit of regular smoking. A possible sex difference was found in the non-contact transition between trier and smoker states, with the transition being more probable in females than in males.     

Guilt and/or self-esteem as consequences of religion

Our discussion begins with a consideration of the various types of religion and of guilt. Both religion and morality function in different ways from individual to individual. All these factors need to be taken into account before we can turn to treatment for the painful experience of guilt and bring about an improved self-esteem.