Influential observations in principal factor analysis

We propose a method for detecting influential observations in iterative principal factor analysis. For this purpose we derive the influence functionsI(x; LL ^T ) andI(x; ) for the common variance matrixT =LL ^T and the unique variance matrix , respectively, in the common factor decomposition =LL ^T + . A numerical example is given for illustration.The authors are grateful to Tomoyuki Tarumi and Atsuhiro Hayashi for their kind permission to use their software Seto/B for drawing Figures 1 and 2 and to anonymous reviewers for comments on the paper.     

Parenting stress in parents of children with attention-deficit hyperactivity disorder and parents of children with learning disabilities

Parenting a child with ADHD can challenge parenting resources and coping. Increasingly, researchers are examining the relationship between the behavior of the child with ADHD and family functioning. While studies have shown inceased parenting stress in parents of children with ADHD, these studies have compared children with ADHD to non-disabled children. This study compares reports of parenting stress among mothers of children with ADHD, mothers of children with learning disabilities and mothers of non-referred children. Results showed that parenting stress was highest for mothers of children with ADHD. Increased parenting stress was associated with child characteristics and, in particular, with externalizing behavior problems.     

The Influence of Distress on Mothers' and Fathers' Reports of Childhood Emotional and Behavioral Problems

This study examined the effect of parental distress on mothers' and fathers' reports of children's emotional and behavioral problems. The subjects were the parents of 696 children aged 10 to 11 or 14 to 15 years living in two-parent families in the community. The study utilized an extended version of the model previously employed by Fergusson, Lynskey, and Horwood (1993) to examine the impact of maternal depression on mothers' reports of children's behavior. In the present study, the extended model was used to assess the impact of distress on reports of childhood externalizing and internalizing problems obtained from both mothers and fathers. The results suggested that distress had little influence on mothers' or fathers' reports of childhood behavior problems. It is concluded that in community studies the size of any bias in mothers' and fathers' reports of childhood behavior problems due to parental distress is likely to be very small and of little clinical significance.     

Beliefs about stories: Parents' and therapists' explanations of childhood difficulties

Therapists and parents were given vignettes describing the behavioural and emotional difficulties of two nine-year-old children and were asked to rate the importance of a number of possible explanations for such difficulties. Broad agreement was found between parents and therapists, but also there were a number of significant differences. Parents endorsed more child centered explanations and put greater emphasis on physical and developmental factors, while therapists endorsed relationships factors and saw the beliefs of other family members as important. Therapists who were parents showed a pattern of responses that lay between those of parents and non-parent therapists.     

The effects of hand and direction parameter preknowledge on choice reaction times

The two studies undertaken investigated how reaction times are affected by preknowledge concerning hand and direction parameters, and the order in which these data are disclosed. In the first experiment, preknowledge was manipulated by selecting 2-CRT pairs which had either a common hand or direction component. Reaction signal information content (as defined by the number of unknown response parameters) was controlled, but no parameter differences emerged. When parameter order was manipulated by sequential precuing, the ‘hand then direction’ order conferred a significant advantage. Motor preparation and response selection explanations for this effect are considered. Various difficulties with the paradigms used are discussed, including those of distinguishing between response selection and motor programming contributions, controlling and inferring the strategies adopted by subjects, and defining task difficulty. The prospects for independently fostering either response identification or motor preparation by means of an appropriate selection of precues are also discussed.     

Teachers' and mothers' assessment of children's behaviors from kindergarten to grade two: Stability and change within and across informants

Consistency between teachers' and parents' ratings of 229 children's prosocial and problem behaviors was investigated from kindergarten through grade two. Intrarater stability was also analyzed. Results indicated moderate but decreasing interrater agreement from kindergarten to grade two for boys on externalizing behaviors. Interrater agreement for the same behavior dimension for girls was moderate and stable, whereas it was low on internalizing behavior problems and prosocial behaviors, for both genders throughout the 3-year period. Moreover, difference between teachers' and parents' ratings of externalizing behaviors increased from kindergarten to grade two. Decreasing level of agreement through time appeared to be related to a reduction of teacher-rated externalizing behaviors not paralleled by a reduction in parent ratings. Analyses were also performed at the item level of the externalization scale to identify which specific behaviors were responsible for the increasing divergence in interrater agreement from kindergarten through grade two. Alternative interpretations were considered in order to account for present and past results. Implications for screening and assessment purposes were discussed.This research was supported by grants from the Social Sciences and Humanities Research Council of Canada and from Québec's Health Research Fund (FRSQ). We wish to thank the authorities and directors of the schools from the Val d'Or School Board as well as the kindergarten, first and second grade teachers, children, and parents for their collaboration. We also thank Lyse Desmarais-Gervais, Daniel Corriveau, Jean Desrosiers and Hélène Boileau for their participation in the data collection or analysis.     

Assessment of incarcerated juvenile delinquents: Agreement across raters and approaches to psychopathology

The purpose of the current study was to examine the agreement across three informants (youth, teacher, caretaker) when rating behaviors of incarcerated juvenile delinquents. Furthermore, the agreement between a dimensional approach (Child Behavior Checklist) and a categorical approach (DSM-III-R) of assessing behavior was examined. Fifty-two delinquent youth were assessed with a structured interview. In addition, the youth, teacher, and caretaker completed the Child Behavior Checklist (CBCL). The results indicated significant correlations across the teacher and caretaker for externalizing types of problems. The youth report form of the CBCL did not correspond to either adult informant. However, the ratings by the teacher and caretaker were related to externalizing types of problems, primarily hyperactivity/inattention, derived from the structured interview with the delinquent. The results suggest that, in the psychological assessment of incarcerated juvenile delinquents, agreement across informants is dependent on multiple factors, including type of behavior assessed and the approach utilized in assessment.This work was supported, in part, by the Juvenile Justice Coordinating Council of Georgia, the Office of Juvenile Justice and Delinquency Prevention, and the University of Georgia's Institute for Behavioral Research.     

The rapid-smoking technique: Subject characteristics and treatment outcome

There is a lack of consistency in findings regarding subject (S) characteristics and the effects of smoking-control programmes. Research workers appear to assume that abstinence and reduction in smoking rate are merely different points in the same continuum, and therefore seek to correlate S variables with percentage reductions in smoking rate. It is argued that abstinence and reduced smoking are more appropriately viewed as potentially discrete outcomes. Conceptualizing outcome in this manner, a discriminant function analysis was employed to determine whether it is possible to differentiate between Ss who do, or do not, abstain following participation in a treatment programme involving rapid-smoking. It was found that it is possible to discriminate between the two groups of Ss. Advantages deriving from this approach to the investigation of S characteristics and treatment outcome are discussed.     

BEHAVIOR ANALYSIS APPLIED TO ENVIRONMENTAL/ECOLOGICAL PROBLEMS; A REVIEW1

Recent applications of operant technology, including the manipulation of environmental conditions and response consequences, have been directed toward the improvement of man-environment relations. This document summarizes the research designs, procedures, results, and conclusions of these recent behavioral interventions for ecological rebalance. Each of the 32 studies reviewed was undertaken since 1970; all studies were relatively successful in changing the probability of an ecology-related response; all studies incorporated basic methodologies applicable for large-scale, community programs; most of the investigations were conducted in field settings (e.g., college campuses, grocery stores, mobile-trailer parks, homes, movie theaters, public campgrounds, and a football stadium). Several of the studies are as yet unpublished. Sources for receiving documentation of the unpublished research are provided in this document. About 50% of the investigations reviewed were designed to influence behaviors related to environmental litter; the others were of behavior-modification programs that substantially increased bus-ridership, decreased lawn-trampling, promoted the purchase of drinks in returnable rather than throwaway containers, initiated a recycling process, or reduced energy consumption. Essentially, the interventions were either preventive in nature (i.e., designed to discourage environment-destructive behaviors before they occur), or remedial (i.e., designed to encourage behaviors that correct an existing environmental problem). Usually, the preventive measures emphasized responses priming (or prompting), while the corrective measures applied some form of positive reinforcement. Response priming was accomplished with modelling techniques, or with written and/or verbal prompts presented either publicly or on a personal, one-to-one basis. Among the positive reinforcement procedures were field applications of token economies, lottery systems, feedback programming, and intergroup contests, as well as individual contingency contracting. Some experimental designs provided for comparisons between the behavioral effects of response priming and positive reinforcement.