Interpreting canonical correlation analysis through biplots of structure correlations and weights

This paper extends the biplot technique to canonical correlation analysis and redundancy analysis. The plot of structure correlations is shown to the optimal for displaying the pairwise correlations between the variables of the one set and those of the second. The link between multivariate regression and canonical correlation analysis/redundancy analysis is exploited for producing an optimal biplot that displays a matrix of regression coefficients. This plot can be made from the canonical weights of the predictors and the structure correlations of the criterion variables. An example is used to show how the proposed biplots may be interpreted.     

Type A behaviour in pre-school children: Interrater reliability, stability over six months and subcomponents

Type A behaviour was measured in 250 boys and 245 girls (ages 3-7) using a Swedish version of Matthews' Youth Test for Health (MYTH). In addition, speech and voice characteristics (speed, loudness, response latency) were measured. Each child was independently rated by two play group leaders and measurements were repeated after a six month interval. Interrater reliability (first session) was 0.76 for both sexes and did not change with the age of the child. Boys obtained significantly (p less than 0.0001) higher scores than girls. Correlations over the six month period were 0.64 and 0.60 (p less than 0.001) for the two possible combinations of different raters and slightly higher (0.75 and 0.68, p less than 0.001) when the same rater was used. Two components of Type A behaviour were identified from a factor analysis of the data: impatience and competitiveness, and they accounted for 57% of the total variance. As for the total scale, boys obtained significantly higher scores than girls on both subscales. Scores on the competitiveness scale increased systematically with age. Speech and voice characteristics correlated significantly with Type A scores (total Type A behaviour: r = 0.50, using different raters, and 0.71, using the same raters, p less than 0.001) and, once again, boys obtained significantly (p less than 0.001) higher scores than girls. The results are in close agreement with the American findings from the original scale. It was concluded that the scale provides a reliable and valid instrument for measuring Type A or Type A-like behaviours in pre-school children.     

Lateralization of defence mechanisms related to creative functioning

Eighty-four undergraduate students were randomly divided into left and right visual half-field groups. They were tested in either visual half-field with a percept-genetic test of anxiety and defense mechanisms (the MCT). The subjects also took a test of creative functioning (the CFT) and degree of lateralization in the MCT was related to level of creativity in the CFT. Subjects low in creativity were significantly lateralized on measures typical for the right visual half-field group (isolation and repression) and tended to differ on a left visual half-field measure (regressive strategies). For high creative subjects no differences were found between the visual half-field groups. Also, high creative persons more often responded with non-hemisphere-specific defenses than low creative ones. The results were interpreted as due to differing levels of transmission of information between the two hemispheres of the brain.     

Normal values for Type A behaviour patterns in Danish men and women and in potential high-risk groups

The Jenkins Activity Survey (JAS) was administered to a normal population of randomly selected Danish adults, to patients consulting a cardiologist, and to physicians in order to compare those groups in terms of their coronary-prone (Type A) behaviour patterns. The standard procedure of rating the JAS was used in order to obtain scores for each of the four subscales: Type A (time urgency and ambitiousness), Factor S (speed and impatience) Factor H (hard-driving and competitive) and Factor J (job involvement). Gender differences were observed in the normal population for each of the four subscale scores, and age-related differences were obtained for Factor J. Elevated scores for Factor S were obtained by physicians and by people in the population who had a cardiovascular disorder. Physicians had also elevated scores for Factor J, whereas their Factor H scores tended to be reduced. No reliable differences in JAS subscale scores were observed between four groups of heart patients (i.e. angina pectoris, arterial hypertension, atrial fibrillation and atherosclerosis), although there was a tendency for Factor J to be elevated in atherosclerosis. The findings provide normal values for JAS scores in Danish men and women, and suggest that some facets of coronary-prone behaviour may be enhanced in Danish high-risk groups.     

Familial similarity in Type A behaviour and physiological measurements as related to sex

Thirty-one families with pre-school children were examined with regard to Type A behaviour and cardiovascular and neuroendocrine measurements. Type A scores (MYTH) of the children from the ages of three to six were positively correlated with independent Type A measurements (Jenkins Activity Survey, Bortner Type A scale) of the parents (significant for fathers but not for mothers). The children's resting systolic blood pressures were significantly correlated with maternal and paternal values, while no significant familial aggregation was found for diastolic blood pressure, heart rate, catecholamine or cortisol excretion. The children's systolic and diastolic blood pressures and adrenaline excretion were significantly correlated between ages three and six. The results are consistent with the assumption that genetic as well as environmental factors contribute to the development of Type A behaviour. No significant association was found between Type A scores and physiological measurements during routine activities in the children or the adults.     

Continuous and discrete latent structure models for item response data

Relations are examined between latent trait and latent class models for item response data. Conditions are given for the two-latent class and two-parameter normal ogive models to agree, and relations between their item parameters are presented. Generalizationss are then made to continuous models with more than one latent trait and discrete models with more than two latent classes, and methods are presented for relating latent class models to factor models for dichotomized variables. Results are illustrated using data from the Law School Admission Test, previously analyzed by several authors.     

计量测验效度的一种方法——测量目标结构空间的实证性因素分析

该文提出了计量测验效度的一种统一方法。首先,根据测量目标由测验编制者提出一组可能的线性拟合模型,拟合模型的集合称作“测量目标结构空间”。然后运用实证性因素分析对各个假设的拟合模型进行多方面的拟合良好性检验。若其中的某一假设模型能最优地拟合预测资料,则该模型中的公共因素的方差总贡献与观测变量的总方差的比就可定义为该测验的效度     

Ethnic differences in psychiatric disorders among adolescent substance abusers in treatment

The present study describes the diagnostic profile of over 800 adolescents admitted to residential therapeutic community programs for treatment of drug abuse and related problems. The relationship between race/ethnicity and psychiatric disturbance is examined, and the association among these factors to outcome is investigated. Over 90% of the sample had a DSM-III-R nonsubstance diagnosis. There were significant differences among the race/ethnic groups on attention deficit-hyperactivity and the disruptive behavior and affective disorders. In general, African-American adolescents yielded the lowest rates of disturbance across all categories of disorders. There was no relationship among race/ethnicity, psychiatric disturbance, and 1-year posttreatment outcomes.     

Effects of a variable-ratio conditioning history on sensitivity to fixed-interval contingencies in rats.

We investigated the possibility that human-like fixed-interval performances would appear in rats given a variable-ratio history (Wanchisen, Tatham, & Mooney, 1989). Nine rats were trained under single or compound variable-ratio schedules and then under a fixed-interval 30-s schedule. The histories produced high fixed-interval rates that declined slowly over 90 sessions; differences as a function of the particular history were absent. Nine control animals given only fixed-interval training responded at lower levels initially, but rates increased with training. Despite differences in absolute rates, rates within the intervals and postreinforcement pauses indicated equivalent development of the accelerated response patterns suggestive of sensitivity to fixed-interval contingencies. The finding that the histories elevated rates without retarding development of differentiated patterns suggests that the effective response unit was a burst of several lever presses and that the fixed-interval contingencies acted on these units in the same way as for single responses. Regardless of history, the rats did not manifest the persistent, undifferentiated responding reported for humans under comparable schedules. We concluded that the shortcomings of animal models of human fixed-interval performances cannot be easily remedied by including a variable-ratio conditioning history within the model.     

Residualanalysis in the polytomous rasch model

Residuals for check of model fit in the polytomous Rasch model are examined. Comparisons are made between using counts for all response pattern and using item totals for score groups for the construction of the residuals. Comparisons are also, for the residuals based on score group totals, made between using as basis the item totals, or using the estimated item parameters. The developed methods are illustrated by two examples, one from a psychiatric rating scale, one from a Danish Welfare Study.