Distinguishing between conduct problem and emotionally disturbed students in secondary school: a five-instrument discriminant analysis

Five instruments, the Differential Test of Conduct and Emotional Problems, Louisville Behavior Checklist, Personality Inventory for Children, 16 PF Test, and Tennessee Self-concept Scale, were given to differentiate between 50 conduct problem and 48 emotionally disturbed students assigned in public school to secondary level classes for the severely emotionally handicapped. Discriminant analysis of each test's rate of classification germane to both a pre-assessment categorization as conduct problem vs emotionally disturbed and a post-assessment classification as no problem vs conduct problem vs emotionally disturbed vs combined problem is presented. The analysis indicated that the Differential Test of Conduct and Emotional Problems, Louisville Behavior Checklist, and Personality Inventory for Children can, with variable effectiveness, significantly classify adolescents into groups using such pre- and post-assessment information.     

Fitting longitudinal reduced-rank regression models by alternating least squares

An alternating least squares method for iteratively fitting the longitudinal reduced-rank regression model is proposed. The method uses ordinary least squares and majorization substeps to estimate the unknown parameters in the system and measurement equations of the model. In an example with cross-sectional data, it is shown how the results conform closely to results from eigenanalysis. Optimal scaling of nominal and ordinal variables is added in a third substep, and illustrated with two examples involving cross-sectional and longitudinal data.Financial support by the Institute for Traffic Safety Research (SWOV) in Leidschendam, The Netherlands is gratefully acknowledged.     

Differential effects of priming at the encoding and judgment stage

Two experiments investigated whether the direction of priming effects depends on the processing stage at which the individual links the prime to a trait that is applicable to the evaluation of an ambiguously described target person. In line with previous research, it is hypothesized that assimilation effects will emerge when primes are processed in terms of a trait concept that is applicable to the encoding task. However, when the primes are not processed in applicable trait terms, they may still affect subsequent Judgments if the individual recalls the prime when judging the target along a trait dimension. In this case, the primes may serve as an anchor, resulting in contrast effects. Two experiments, in which subjects were primed with names of prototypically nice or hostile famous individuals under instructions that did or did not prompt subjects to process the prime in applicable trait terms, supported these hypotheses. Implications for the emergence of priming effects in everyday social interaction are discussed.     

Influences of semantic and syntactic context on open- and closed-class words

Event-related potentials (ERPs) were recorded as subjects read semantically meaningful, syntactically legal but nonsensical and random word strings. The constraints imposed by formal sentence structure alone did not reduce the amplitude of the N400 component elicited by open-class words, whereas semantic constraints did. Semantic constraints also eliminated the word-frequency effect of a larger N400 for low-frequency words. Responses to closed-class words exhibited reduced N400 amplitudes in syntactic and congruent sentences, indicating that formal sentence structure placed greater restrictions on closed-class words than it did on open-class words. However, unlike the open-class results, the impact of sentence context on closed-class words was stable across word positions, suggesting that these syntactic constraints were applied only locally. A second ERP component, distinct from the N400, was elicited primarily by congruent closed-class words.     

A faith for all seasons

A FAITH FOR ALL SEASONS:ISLAM AND WESTERN MODERNITY. By Shabbir Akhtar. London: Bellew Publishing, 1990. 251pp. Hb. £25.00. ISBN 0–947792–41–4.     

A note on partitioned determinants

A formula for the determinant of a partitioned matrix, possibly with singular submatrices, is derived and applied to some psychometric and numerical problems.     

Generalized eigenvalue problems with positive semi-definite matrices

In a recent paper in this journal McDonald, Torii, and Nishisato show that generalized eigenvalue problems in which both matrices are singular can sometimes be solved by reducing them to similar problems of smaller order. In this paper a more extensive analysis of such problems is used to sharpen and clarify the results of McDonald, Torii, and Nishisato. Possible extensions are also indicated. The relevant mathematical literature is reviewed briefly.     

Scene perception: Detecting and judging objects undergoing relational violations

Five classes of relations between an object and its setting can characterize the organization of objects into real-world scenes. The relations are (1) Interposition (objects interrupt their background), (2) Support (objects tend to rest on surfaces), (3) Probability (objects tend to be found in some scenes but not others), (4) Position (given an object is probable in a scene, it often is found in some positions and not others), and (5) familiar Size (objects have a limited set of size relations with other objects). In two experiments subjects viewed brief (150 msec) presentations of slides of scenes in which an object in a cued location in the scene was either in a normal relation to its background or violated from one to three of the relations. Such objects appear to (1) have the background pass through them, (2) float in air, (3) be unlikely in that particular scene, (4) be in an inappropriate position, and (5) be too large or too small relative to the other objects in the scene. In Experiment I, subjects attempted to determine whether the cued object corresponded to a target object which had been specified in advance by name. With the exception of the Interposition violation, violation costs were incurred in that the detection of objects undergoing violations was less accurate and slower than when those same objects were in normal relations to their setting. However, the detection of objects in normal relations to their setting (innocent bystanders) was unaffected by the presence of another object undergoing a violation in that same setting. This indicates that the violation costs were incurred not because of an unsuccessful elicitation of a frame or schema for the scene but because properly formed frames interfered with (or did not facilitate) the perceptibility of objects undergoing violations. As the number of violations increased, target detectability generally decreased. Thus, the relations were accessed from the results of a single fixation and were available sufficiently early during the time course of scene perception to affect the perception of the objects in the scene. Contrary to expectations from a bottom-up account of scene perception, violations of the pervasive physical relations of Support and Interposition were not more disruptive on object detection than the semantic violations of Probability, Position and Size. These are termed semantic because they require access to the referential meaning of the object. In Experiment II, subjects attempted to detect the presence of the violations themselves. Violations of the semantic relations were detected more accurately than violations of Interposition and at least as accurately as violations of Support. As the number of violations increased, the detectability of the incongruities between an object and its setting increased. These results provide converging evidence that semantic relations can be accessed from the results of a single fixation. In both experiments information about Position was accessed at least as quickly as information on Probability. Thus in Experiment I, the interference that resulted from placing a fire hydrant in a kitchen was not greater than the interference from placing it on top of a mail ? in a street scene. Similarly, violations of Probability in Experiment II were not more detectable than violations of Position. Thus, the semantic relations which were accessed included information about the detailed interactions among the objects—information which is more specific than what can be inferred from the general setting. Access to the semantic relations among the entities in a scene is not deferred until the completion of spatial and depth processing and object identification. Instead, an object's semantic relations are accessed simultaneously with its physical relations as well as with its own identification.