Youth Action Research for Prevention: A Multi-level Intervention Designed to Increase Efficacy and Empowerment Among Urban Youth

Youth Action Research for Prevention (YARP), a federally funded research and demonstration intervention, utilizes youth empowerment as the cornerstone of a multi-level intervention designed to reduce and/or delay onset of drug and sex risk, while increasing individual and collective efficacy and educational expectations. The intervention, located in Hartford Connecticut, served 114 African-Caribbean and Latino high school youth in a community education setting and a matched comparison group of 202 youth from 2001 to 2004. The strategy used in YARP begins with individuals, forges group identity and cohesion, trains youth as a group to use research to understand their community better (formative community ethnography), and then engages them in using the research for social action at multiple levels in community settings (policy, school-based, parental etc.) Engagement in community activism has, in turn, an effect on individual and collective efficacy and individual behavioral change. This approach is unique insofar as it differs from multilevel interventions that create approaches to attack multiple levels simultaneously. We describe the YARP intervention and employ qualitative and quantitative data from the quasi-experimental evaluation study design to assess the way in which the YARP approach empowered individual youth and groups of youth (youth networks) to engage in social action in their schools, communities and at the policy level, which in turn affected their attitudes and behaviors.     

Die Ausbildung der mathematischen Zeichensprache und ihr Einfluss auf die Entwicklung der mathematischen Problemstellung

Ohne ZusammenfassungStark gekürzte Fassung.     

A counterexample to the rigidity assumption in the visual perception of structure from motion

It has been proposed that the human visual system prefers perceptions of objects that are rigid or undergo minimum form change. A counterexample is presented in which a rigid two-dimensional figure rotating in the frontal plane is perceived as a distorting three-dimensional shape. It is argued that this perception results from the stimulation of automatic processes for perceiving size change, and that these processes are not subject to a general rigidity assumption.     

The algebra of factorial indeterminancy

Certain properties and consequences of factor indeterminancy are deduced from an orthogonal transformation derived by Ledermann [5]. The first deduction is the matrix of cosines between maximally distinct factor axes which represent the same factor solution. This result is used to investigate the indeterminancy of factor extensions.     

Men's sexual self-schema

Sexual self-schemas are cognitive generalizations about sexual aspects of oneself. In Part 1, a measure of men's sexual self-schema is developed. Studies of test-retest and internal consistency reliability and validity studies of factor analysis, internal structure, convergent and discriminant validity, process, group difference, and change are provided. The construct consists of 3 dimensions: passionate-loving, powerful-aggressive, and open-minded-liberal traits. In Part 2, the data suggest that men's sexual schema is derived from past sexual experience, is manifest in current sexual experience, and guides future sexual behavior. In Part 3, the data document the cognitive processing aspects of sexual schema. Consistent with the investigators' schema research with women, these data substantiate the importance of cognitive representations of sexuality.     

The discrimination of heading from optic flow is not retinally invariant.

Three experiments were conducted to determine whether the discrimination of heading from optic flow is retinally invariant and to determine the importance of acuity in accounting for heading eccentricity effects. In the first experiment, observers were presented with radial flow fields simulating forward translation through a three-dimensional volume of dots. The flow fields subtended 10 degrees of visual angle and were presented at 0 degree, 10 degrees, 20 degrees, and 40 degrees of retinal eccentricity. The observers were asked to indicate whether the simulated movement was to the right or the left of a target that appeared at the end of the display sequence. Eye movements were monitored with an electrooculogram apparatus. In a second experiment, static acuity thresholds were derived for each of the observers at the same retinal eccentricities. There was a significant increase in heading detection thresholds with retinal eccentricity (from 0.92 degree at 0 degree retinal eccentricity to 3.47 degrees at 40 degrees). An analysis of covariance indicated that the variation in sensitivity to radial flow, as a function of retinal eccentricity, is independent of acuity. Similar results were obtained when the Vernier acuity of observers was measured. These results suggest that the discrimination of heading from radial flow is not retinally invariant.     

Why do Alzheimer patients have difficulty with pronouns? Working memory, semantics, and reference in comprehension and production in Alzheimer's disease

Three experiments investigated the extent to which semantic and working-memory deficits contribute to Alzheimer patients' impairments in producing and comprehending referring expressions. In Experiment 1, the spontaneous speech of 11 patients with Alzheimer's disease (AD) contained a greater ratio of pronouns to full noun phrases than did the spontaneous speech produced by 9 healthy controls. Experiments 2 and 3 used a cross-modal naming methodology to compare reference comprehension in another group of 10 patients and 10 age-matched controls. In Experiment 2, patients were less sensitive than healthy controls to the grammatical information necessary for processing pronouns. In Experiment 3, patients were better able to remember referent information in short paragraphs when reference was maintained with full noun phrases rather than pronouns, but healthy controls showed the reverse pattern. Performance in all three experiments was linked to working memory performance but not to word finding difficulty. We discuss these findings in terms of a theory of reference processing, the Informational Load Hypothesis, which views referential impairments in AD as the consequence of normal discourse processing in the context of a working memory impairment.     

Influence of sex and gender roles on high school status systems

Past research has indicated significant sex differences in determinants of male and female high school students' status as measured by how subjects would like to have been remembered from their high school years. In order to determine if remembrance preference is sex or gender role related, 671 subjects were administered the Bem Sex-Role Inventory (BSRI) and a questionnaire asking if they most wanted to be remembered from high school as a brilliant student, leader in activities, athletic star or most popular. Using both the median split and t-ratio procedures in scoring the BSRI, 206 subjects were selected because they were sex-typed (masculine males, feminine females), cross sex-typed (masculine females, feminine males), or androgynous (scoring high on both masculine and feminine traits). To find a model of best fit, the data were subjected to a log-linear analysis. The variables included were sex, gender role, and remembrance preference. Rather than sex being the influential factor, the model of best fit was a gender role by remembrance preference interaction. If subjects were masculine, they were more likely to choose athletic star than were feminine or androgynous subjects. Most popular and leader in activities were both more likely to be chosen by feminine and androgynous subjects. All groups chose brilliant student more often than any other category. It was concluded that some previously designated sex differences may instead be differences in gender role. Further research should address the distinction between the two.