阅读中自然学习生词的实验研究

本研究对儿童阅读时从语境中自然学习生词的过程及其多个影响因素进行了探讨。301名三、五年级小学生参加了实验。首先要求他们阅读文章,然后测验他们对文章中生词的知识。本研究在不同年级和能力的儿童中都发现了显著的自然学习效应。结果还表明,词的概念难度、词结构的语义透明度、语境线索强度和儿童课外阅读量对儿童的自然学习有重要影响。     

Onset of obsessive-compulsive disorder: premorbid conditions and prodromal phase

This article focuses on the clinical onset of obsessive-compulsive disorder (OCD), specifically addressing the age of onset, gradual and acute onset, and whether there are some types of premorbid conditions or a prodromal phase that predispose individuals to the onset of OCD. Clinical and epidemiological studies have come to different conclusions regarding age at onset as well as regarding differences between the sexes. Data gleaned from research to date have demonstrated a relationship between OCD and obsessive-compulsive personality disorder (OCPD), although OCPD does not appear to be the more prevalent personality disorder among patients with OCD. Preliminary research has suggested that Axis I disorders may predispose individuals to OCD onset; however, the significance of this relationship remains to be clarified. Evidence of the association between OCD and subthreshold obsessive-compulsive syndrome suggests that these disorders lie on a continuum of severity, with some cases developing OCD while others do not.     

Body image and self-esteem in adolescent ballet dancers.

Body-image disturbances and low self-esteem have been implicated in the pathogenesis of eating disorders. This study investigated self-perception of body and personality among adolescent ballet dancers in a cross-sectional survey. Two questionnaires assessing "my body right now" and "my personality right now," using semantic differentials were completed by 90 ballet school students and 156 controls. Adolescent female dancers (ages 13 to 17 years) scored higher than age-matched controls and 11- to 12-yr. old peers on Undesirability and Sensitivity for personality and Unattractiveness for body. For both subscales of personality, differences were also found between male and female dancers; female ballet students scored higher. Within the control group a difference could be found only for Sensitivity on which girls scored higher than boys. Male dancers did not differ from controls except for a lower score on the Body mass measure. Adolescent female dancers showed a distinct answering profile for 7 of 16 semantic differentials in each questionnaire implicating less favorable body image and self-esteem. Interventions focused particularly on enhancing self-esteem may be useful in the prevention of psychopathology in adolescent ballet dancers.     

Statistical properties of the rWG(J) index of agreement

L. R. James, R. G. Demaree, and G. Wolf (1984) introduced rWG(J) to estimate interrater agreement for a group. This index is calculated by comparing an observed group variance with an expected random variance. As researchers have gained experience using this index, several questions have arisen. What are the consequences of replacing values beyond the unit interval by 0? What is the dependence of rWG(J) on the group size? The authors' simulations show that a positive bias is caused by the truncation, but for large population values of rWG(J) it is negligible. Also, in this case, the group size has no effect on the expected value of rWG(J). For inference on rWG(J), researchers can exploit the availability of computers to simulate data from the hypothesized distribution and then compare the simulation results for rWG(J) with the actual values. In addition, it is shown how the bootstrap method can be used for comparing the indices of 2 groups.     

Conditioning of a discriminative drug stimulus: Overshadowing and blocking like procedures

Interactions between a drug discriminative stimulus ( D , 17.5 mg/kg of pentobarbital vs. N , saline) and exteroceptive stimulus conditions (light vs. dark) were examined in a T-maze, shock-escape task using conditioning procedures pertaining to the phenomena of "overshadowing" and "blocking". From an operational point of view, in the "overshadowing" procedure the stimulus compound is introduced from the outset of the training, whereas in the "blocking" procedure the stimuli components are introduced sequentially. When the compound discriminations were established, dose-generalization tests with various doses of pentobarbital (range 5.6–17.5 mg/kg) as well as saline (1 ml/kg) were carried out under both elements (light and dark) of the exteroceptive stimulus dimension. Prior training with drug ( D vs. N ) neutralized the potential influence of the exteroceptive dimension (light vs. dark); conversely training with the exteroceptive stimuli prior to the drug training accentuated the control over behavior by the visual stimuli. Dose-generalization results intermediate to those described above were observed in the group trained to discriminate the stimulus compound ( D plus light vs. N plus dark) from the outset of training. It may therefore be concluded that exteroceptive stimuli can compete with interoceptive drug stimuli for associative strength in the procedure used. Thus, the formal similarities between drug discriminative stimuli and more conventionally studied exteroceptive, sensory signals are furthered by the data.     

Differential effects of environmental enrichment on the open-field behavior of wild and domestic Norway rats.

Early postweaning experience in an enriched environment had a greater influence on the open-field behavior and body weight of wild Norway rats than of their domestic counterparts. Genetic changes accompanying the domestication process may have reduced the relative impact of postweaning experience on the development of the domestic rat's response to changes in its environment.     

Parental Influence on Students' Educational Choices in the United States and Germany: Different Ramifications—Same Effect?

Despite the historical trend in all Western societies to increase educational participation irrespective of students' social origin, the correlation between parents' education and socio-economic status and the educational outcomes of their offspring remains a rather universal phenomenon. Although comparative studies have consistently found this association in various nations which differ in many ways in their educational systems, little is known about the mechanism behind this effect. Drawing on the assumption that career decision points are the major gateway for social background influences, we assume that similarities, as well as differences in the structure of the correlation between parents' socioeconomic background and students' school success, can be explained. Using two longitudinal data sets from the United States (N=1425) and Germany (N=1755) covering the school careers from Grade 7 to Grade 10, the analyses supported the hypothesis that (a) achievement information is the best predictor of career relevant decisions in both nations, (b) parents' background variables are independent additional predictors of career decision but not for actual learning progress, and (c) the assumed accumulation process of social background influences is more pronounced in the German than in the U.S. school system.     

The personal-group discrepancy: Is there a common information basis for personal and group judgment?

In contrast to motivational accounts of the personal-group discrepancy, results from this article suggest that the discrepancy is explained by aggregating different sets of comparison outcomes for either personal or group ratings. Results from a longitudinal study with East German (the minority group) and West German (the majority group) samples confirm the personal-group discrepancy and support our approach. First, social comparisons influenced evaluations of economic situation at both group and personal levels. Second, ratings of group versus personal economic situation were based on different sets of comparisons. Third, the mean structure of both sets of comparison outcomes mirrored the personal-group discrepancy. Fourth, an interaction between personal-group discrepancy and group status supported the authors' suggestions-concerning the direction of the discrepancy.