Comparison of 1 and 2 days per week of strength training in children

The purpose of this study was to compare the effects of 1 and 2 days per week of strength training on upper body strength, lower body strength, and motor performance ability in children. Twenty-one girls and 34 boys between the ages of 7.1 and 12.3 years volunteered to participate in this study. Participants strength trained either once per week (n = 22) or twice per week (n = 20) for 8 weeks at a community-based youth fitness center. Each training session consisted of a single set of 10-15 repetitions on 12 exercises using child-size weight machines. Thirteen children who did not strength train served as age-matched controls. One repetition maximum (1RM) strength on the chest press and leg press, handgrip strength, long jump, vertical jump, and flexibility were assessed at baseline and posttraining. Only participants who strength trained twice per week made significantly greater gains in 1RM chest press strength, compared to the control group (11.5 and 4.4% respectively, p < .05). Participants who trained once and twice per week made gains in 1RM leg press strength (14.2 and 24.7%, respectively) that were significantly greater than control group gains (2.4%). On average, participants who strength trained once per week achieved 67% of the 1RM strength gains. No significant differences between groups were observed on other outcome measures. These findings support the concept that muscular strength can be improved during the childhood years and favor a training frequency of twice per week for children participating in an introductory strength training program.     

An Evaluation of Two Hands-On Lab Styles for Plant Biodiversity in Undergraduate Biology

We compared learning cycle and expository formats for teaching about plant biodiversity in an inquiry-oriented university biology lab class (n = 465). Both formats had preparatory lab activities, a hands-on lab, and a postlab with reflection and argumentation. Learning was assessed with a lab report, a practical quiz in lab, and a multiple-choice exam in the concurrent lecture. Attitudes toward biology and treatments were also assessed. We used linear mixed-effect models to determine impacts of lab style on lower-order cognition (LO) and higher-order cognition (HO) based on Bloom''s taxonomy. Relative to the expository treatment, the learning cycle treatment had a positive effect on HO and a negative effect on LO included in lab reports; a positive effect on transfer of LO from the lab report to the quiz; negative impacts on LO quiz performance and on attitudes toward the lab; and a higher degree of perceived difficulty. The learning cycle treatment had no influence on transfer of HO from lab report to quiz or exam; quiz performance on HO questions; exam performance on LO and HO questions; and attitudes toward biology as a science. The importance of LO as a foundation for HO relative to these lab styles is addressed.     

An intervention approach for children with teacher- and parent-identified attentional difficulties

Using a multimodal and multi-informant method for diagnosis, we selected 33 children by teacher and parent nomination for attention and work completion problems that met DSM-IV criteria for attention-deficit/hyperactivity disorder (ADHD). Of the 33 children in this group, 21 participated in the initial intervention, and 12 were placed in an ADHD control group and received the intervention after pre- and posttesting. A similarly selected group of 21 children without difficulties in attention and work completion served as a control group. Each child was assessed on pre- and posttest measures of visual and auditory attention. After an 18-week intervention period that included attention and problem-solving training, all children in the intervention and control groups were retested on visual and auditory tasks. Children in both ADHD groups showed significantly poorer initial performance on the visual attention task. Whereas the ADHD intervention group showed commensurate performance to the nondisabled control group after training, the ADHD control group did not show significant improvement over the same period. Auditory attention was poorer compared to the control group for both ADHD groups initially and improved only for the ADHD intervention group. These findings are discussed as a possible intervention for children with difficulties in strategy selection in a classroom setting.     

Three studies of factors affecting the attitudes of blacks and females toward the pursuit of science and science-related careers

This study involved the development of an instrument, the Science Career Predictor Scale (SCPS), which assesses seven factors thought to be involved with science career choices: teacher/counselor encouragement, participation in science-related hobbies and activities, academic self-image, science-related career interest, parental encouragement and support, the perceived relevance of mathematics and science, and mathematics and science ability. This instrument was administered to a sample of 522 middle and high school students, and a sample of 185 students from an historically black university, and the effects of such factors as sex, race, personal acquaintance with a scientist, and type of community (rural or urban) on the above-mentioned variables were ascertained using a multivariate analysis of covariance with age as the covariate. A separate study on a sample of 81 high school students looked at race and gender differences in critical thinking abilities as measured by the Watson-Glaser Critical Thinking appraisal, and how these abilities correlated with scores on the Science Career Predictor Scale. These studies produced several significant findings. Female subjects did produce significantly lower scores on the career interest factor. Black students actually had significantly higher science-career preference scores than their white counterparts. However, blacks scored significantly lower on the measure of critical thinking ability. Across both races and both sexes, however, the major factor affecting science-related career decisions appears to be personal contact with a scientist. The implications of these findings are discussed, along with possible strategies for increasing the participation of these groups in science.     

Teacher help for conceptual level raising in mathematics

A field study with 16-year-old students in senior general secondary education was undertaken with the following research question: “Do students working in pairs on investigation tasks with the computer attain more conceptual level raising in mathematics when they are supported by a teacher who stimulates their interaction (process help) than when they are supported by a teacher who gives mathematical help (product help)?” Students in both conditions improved, but the two types of help showed no significant difference in level raising. Also, students in both conditions had serious problems with the learning materials, and wanted the teacher to explain and correct more. For students at this level of education, learning with investigation tasks in small groups appears to be very difficult.     

Conceptual learning in relation to near and far transfer in the secondary school subject of economics

In this study we investigated the effects of two treatments supplementing students’ (16 to 18 years of age and in pre-university education) regular course in economics. One treatment, labelled concept treatment, aimed at the solidification of the students’ knowledge about economic concepts and their interrelations. The other treatment, labeled context treatment, aimed at the solidification of the connections between economic concepts and practical contexts. The aim of the study was to find out which treatment was most effective in meeting two demands that have been made by educators and advisory boards. The first demand is that students should gain competence in analysing practical problems from an economic perspective. The second demand is that students should be prepared for transfer of what they learned in the lessons to problems that are new to them.