Flavor-evaluative conditioning is unaffected by contingency knowledge during training with color-flavor compounds

In two experiments, participants inspected and drank a series of drinks, half of which contained sugar and half unpalatable Tween20 (tween). Each sugar and tween drink had a particular flavor and color. Following this training, the flavors of the sugar drinks were assigned higher hedonic evaluations than were those of the tween drinks, even though the participants did not reliably report which flavors had been present in the sugar and tween drinks during training. Moreover, the evaluative conditioning of the flavors was unaffected by whether or not the colors alone had been pretrained to predict the presence of sugar or tween in the drinks. In accord with Baeyens, Eelen, van den Bergh, and Crombez (1990), we conclude that flavor-evaluative conditioning is not mediated by contingency learning.     

Maintenance of responding when reinforcement becomes delayed

In four experiments with rats, we examined the persistence of behavior when reinforcement was switched from immediate to delayed. In Experiment 1, lever pressing elicited by instrumental training with immediate reinforcement continued when a 20-sec delay of reinforcement was introduced (easy-to-hard condition), whereas when the delay condition was introduced from the start (hard-to-hard condition), responding remained low throughout. A similar result was obtained in Experiment 2, in which lever pressing was elicited by a classical conditioning (autoshaping) procedure. In Experiment 3, rats initially trained with delayed reinforcement continued to respond at a low rate when switched to immediate reinforcement (hard-to-easy condition). By measuring magazine entry (goal tracking) as well as lever pressing (sign tracking) in Experiment 4, we confirmed that such transfer effects at least partly involve the persistence of whatever type of behavior was initially dominant.     

Explanations of attitudes to change: Colombian mathematics teachers’ conceptions of the crucial determinants of their teaching practices of beginning algebra

This article arises from a study whose overall purpose was to investigate the relationship between Colombian mathematics teachers’ conceptions of beginning algebra and their conceptions of their own teaching practices. The teachers’ understandings of their teaching practices were explored with a view to unravelling their conceptions of change in their teaching. Focusing on the perspectives of teachers afforded opportunities that exposed the powerful role that the teachers’ conceptions of social/institutional factors of teaching played in their conceptions of their practices. The degree to which the teachers attributed these (external) factors as crucial reasons for what they do in their teaching was the basis of a categorisation of their conceptions of the crucial determinants of their teaching practices into three types. The findings are particularly relevant to our understanding of the stability of mathematics teaching approaches in the Colombian context but have likely implications for a range of international education contexts. Specific implications for the development of the research into teachers’ conceptions of mathematics and its teaching, and for teacher education programmes are presented.

Listening and reflecting: an introduction to the special issue

The topic of listening has been broadly neglected in educational studies. This special issue presents studies on the connections between listening and reflecting in educational contexts.

Qualitative and quantitative analysis of goat ovaries,follicles and oocytes in view of in vitro production of embryos

Goat ovaries were collected from the slaughterhouse and categorized as right, left, corpus luteum （CL）-present and -absent group and evaluated on the basis of weight （g）, length （cm）, width （cm）, number of follicles, follicles aspirated and number and state ofcumulus-oocyte-complexes （COCs）. Comparatively higher weight [（0.66±0.02） vs （0.64±0.02） g], length [（1.17±0.02） vs （1.1 ±0.02） cm] and width [（0.77±0.02） vs （0.74±0.02） cm] were found in right ovaries than those of left. On the other hand significantly （P〈0.05） higher weight [（0.71±0.03） vs （0.64±0.01） g] and width [（0.76±0.03） vs （0.75±0.01） cm] were found in CL-present group than those of CL-absent group of ovaries. The left ovaries contained comparatively higher number of normal COCs [（1.06±0.09） per ovary] than fight ovaries [（1.03±0.10） per ovary] and the similar trend was found in total number of follicles [（4.51±0.25） vs （4.30±0.23） per ovary] and follicles aspirated [（2.55±0.14） vs （2.52±0.12） per ovary]. But the total COCs per ovary was almost similar in both ovaries [right and left： （1.85±0.12） and （1.85±0.11） per ovary, respectively]. Higher number of total COCs [（1.87±0.09） vs （1.76±0.16） per ovary], total number of follicles [（4.45±0.19） vs （4.16±0.37） per ovary], follicles aspirated [（2.55±0.10） vs （2.48±0.21） per ovary] and normal COCs [（1.12±0.07） vs （0.76±0.14） per ovary] were found in CL-absent group than those of CL-present group of ovaries.     

Teaching without a textbook: strategies to focus learning on fundamental concepts and scientific process

Note from the Editor     

Teachers' education, classroom quality, and young children's academic skills: results from seven studies of preschool programs

In an effort to provide high-quality preschool education, policymakers are increasingly requiring public preschool teachers to have at least a Bachelor's degree, preferably in early childhood education. Seven major studies of early care and education were used to predict classroom quality and children's academic outcomes from the educational attainment and major of teachers of 4-year-olds. The findings indicate largely null or contradictory associations, indicating that policies focused solely on increasing teachers' education will not suffice for improving classroom quality or maximizing children's academic gains. Instead, raising the effectiveness of early childhood education likely will require a broad range of professional development activities and supports targeted toward teachers' interactions with children.     

Income is not enough: incorporating material hardship into models of income associations with parenting and child development

Although research has clearly established that low family income has negative impacts on children's cognitive skills and social-emotional competence, less often is a family's experience of material hardship considered. Using the Early Childhood Longitudinal Study, Kindergarten Class of 1998-1999 (N=21,255), this study examined dual components of family income and material hardship along with parent mediators of stress, positive parenting, and investment as predictors of 6-year-old children's cognitive skills and social-emotional competence. Support was found for a model that identified unique parent-mediated paths from income to cognitive skills and from income and material hardship to social-emotional competence. The findings have implications for future study of family income and child development and for identification of promising targets for policy intervention.     

The dyadic nature of bullying and victimization: testing a dual-perspective theory

For this study, information on Who Bullies Who was collected from 54 school classes with 918 children (M age = 11) and 13,606 dyadic relations. Bullying and victimization were viewed separately from the point of view of the bully and the victim. The two perspectives were highly complementary. The probability of a bully-victim relationship was higher if the bully was more dominant than the victim, and if the victim was more vulnerable than the bully and more rejected by the class. In a bully-victim dyad, boys were more often the bullies. There was no finding of sex effect for victimization. Liking reduced and disliking increased the probability of a bully-victim relationship.     

Marital conflict and conduct problems in Children of Twins

The Children-of-Twins design was used to test whether associations between marital conflict frequency and conduct problems can be replicated within the children of discordant twin pairs. A sample of 2,051 children (age 14-39 years) of 1,045 twins was used to estimate the genetic and environmental influences on marital conflict and determine whether genetic or environmental selection processes underlie the observed association between marital conflict and conduct problems. Results indicate that genetic and nonshared environmental factors influence the risk of marital conflict. Furthermore, genetic influences mediated the association between marital conflict frequency and conduct problems. These results highlight the need for quasiexperimental designs in investigations of intergenerational associations.