Cluster analysis in school psychology: An example

This investigation demonstrates the use of Ward's method of cluster analysis to uncover the underlying classification structure in a group of children (N = 200) referred for psychological evaluations by their public school teachers. Data were acquired on children's intellectual development, academic achievement, and social adjustment. The cluster solution identifies six groups of children which are statistically distinct. All three measurement areas are important in distinguishing among the different groups. The six-group solution accounted for appreciable amounts (95%) of the variability in the three measurement areas. Implications for psychologists working in the schools are discussed.     

Developmental trends in free classification: Evidence for a new conceptualization of perceptual development

Two studies are reported to explore the hypothesis that young children perceive integrally some stimuli that older children perceive separably. In both, kinder-garteners, second graders, and fifth graders (approximately 5, 8, and 11 years old) are required to classify sets of stimuli that vary in size and brightness. Triads are used in Experiment 1 and tetrads are used in Experiment 2. Also, in Experiment 2, second classifications, judgments of which classification is “best,” and verbal justifications for classifications are obtained. The general finding is that the kinder-garten data systematically implicate integrality of size and brightness while the fifth-grade data systematically implicate separability of size and brightness. The second-grade data are more ambiguous. Issues related to refining the developmental hypothesis and to extending its supportive data base are considered in a final discussion.     

What the classical aphasia categories can't do for us, and why

A good deal of activity in contemporary aphasia research goes under the label "neurolinguistics." What characterizes this enterprise is, among other things, its goal of identifying neurally realized computational subsystems that support language processing. In this essay the thesis is put forward that this goal will not be served by the continued exploitation of the classical (Wernicke-Lichtheim) taxonomic categories. These categories, it is argued, cannot by virtue of their "polytypic" structure support the relevant neurolinguistic generalizations.     

A strong developmental theory of field dependence-independence

Assume an X-linked gene in two alleles mediates performance on field dependent-independent tests such as the rod-and-frame test. Only the recessive gene with relative frequency q facilitates field independence. Other genotypes lead to field dependence. Under a simple genetic model, field dependence-independence may be viewed as outcomes of a discrete random variable B with field independent and dependent probabilities π_iq and 1 ? π_iq for men, and π_iq² and 1 ? π_iq² for women, respectively. The parameter π_i is a maturational ageindexed parameter, 0 < π_i ≤ 1, monotonically increasing with development until maturity when π_k = 1. Observations of performance are made on a random variable W of the form W = B + N, where N is normal in distribution independent of B; N represents a composite of influences including error. The model implies testable age-related between- and within-sex predictions regarding E(W) and Var(W), predictions which appear to coincide with major empirical findings; it also generates novel predictions. For instance, W is a mixture of normals distribution. The model is briefly evaluates in two data sets.     

A test of a method for quantifying amount, complexity, and arrangement of play resources in the preschool classroom

This study was a test of the feasibility of a method for quantifying the physical features of a high quality preschool setting. Play resources were selected and arranged for: (a) visibility and access, (b) variations in complexity level, and (c) availability of alternate selections for play choices. Independent analyses from two urban day care settings (N=60) provided concurrent replication of the test of the hypotheses. As predicted, significant increases in participation were recorded from baseline to experimental treatment, and concomitant decreases from treatment to post-treatment. Conflicts rarely occurred during baseline or treatment. However, the increase in conflicts during post-treatment was viewed as a significant effect of the cessation of treatment. Treatment condition did not affect the statistical prevalence of waiting and watching behaviors, but did appear to influence the functions served by these noninteractions. Implications of these results for application by early childhood personnel are offered.     

Children and adolescents as producers of their own development

Interest in the historically changing contexts of human life has been associated with the elaboration of a life-span view of human development. This view holds that all levels of the context, including the biological, psychological, and sociocultural, change in reciprocal relation to one another. As a consequence of being embedded in a context which they both influence and are influenced by, children and adolescents may promote their own development. One way this occurs is that as a consequence of their characteristics of physical and behavioral individuality people promote differential reactions in their socializing others (e.g., parents, teachers, or peers); these reactions feed back affecting further development. My colleagues and I have conducted research that describes such child and adolescent contributions to development. We have focused on characteristics of physical individuality, such as body type and physical attractiveness, and on characteristics of behavioral individuality, such as behavioral style or temperament. Findings from these studies are conceptualized in terms of a person-context “goodness-of-fit” model. Adaptive development is associated with congruence, or fit, between a person's attributes of individuality and the demands of his or her setting. Implications of this research for illustrating the use of the life-span perspective, and for theory in and practice of intervention, are discussed.     

Preschoolers' counting: principles before skill

Three- to 5-year-old children participated in one of 4 counting experiments. On the assumption that performance demands can mask the young child's implicit knowledge of the counting principles, 3 separate experiments assessed a child's ability to detect errors in a puppet's application of the one-one, stable-order and cardinal count principles. In a fourth experiment children counted in different conditions designed to vary performance demands. Since children in the errror-detection experiments did not have to do the counting, we predicted excellent performance even on set sizes beyond the range a young child counts accurately. That they did well on these experiments supports the view that errors in counting—at least for set sizes up to 20—reflect performance demands and not the absence of implicit knowledge of the counting principles. In the final experiment, where children did the counting themselves, set size did affect their success. So did some variations in conditions, the most difficult of which was the one where children had to count 3-dimensional objects which were under a plexiglass cover. We expected that this condition would interfere with the child's tendency to point and touch objects in order to keep separate items which have been counted from those which have not been counted.     

Primary influencers of initial vocational choices for college women

This study of 597 entering college women investigated the characteristics of people they named as the primary influencers for their initial choices of major. College major was considered analogous to vocational field since the sample of students overwhelmingly gave career goals as reasons for choosing a particular major. Characteristics of these primary influencers were compared with those of a sample of individuals influencing male choices. In addition, characteristics of influencers were compared between those influencing females choosing traditional and nontraditional majors. The results indicate that most students, regardless of gender, were influenced by males, particularly fathers. However, a notable percentage of female students, especially those in traditional fields, were influenced by females. Students whose primary influencers were in fields closely related to their own vocational choices reported being more certain of their choices than students citing influencers in unrelated fields. These findings have implications for model-observer similarity, and may necessitate distinguishing between influential people who provide reinforcement for a choice of major and those who provide specific vocational modeling as well as reinforcement for that choice.     

Training research in aging on the fluid ability of inductive reasoning

The modifiability of older adults' performance on Induction tasks was examined through cognitive training. The posttraining performance of 52 older adults ($\text{X}\text{age = 70.3}\text{years}$) was assessed with regard to a transfer-of-training paradigm and maintenance of training effects at three posttests (one week, one month, six months). A pattern of differential training transfer across the posttest battery of fluid and crystallized intelligence measures was predicted, with the largest training effects expected for near transfer (Induction) measures. The predicted pattern of training transfer was obtained at one-week and one-month posttests, with significant training effects to the nearest Induction measure. Large retest (practice) effects across posttests also occurred for training and control groups. This research contributes to the position that modifiability of intellectual performance through cognitive intervention extends across the adult life span.