An intensification approach to double-block algebra: A pilot implementation of Intensified Algebra in a large urban school district

Double-block instruction has become a popular strategy for supporting struggling mathematics students in algebra I. Despite its widespread adoption, little consistent evidence supports the attributes of a successful double-block design or the effectiveness of this instructional strategy. In this study, the authors examine a pilot implementation of a double-block strategy—instantiated in the program Intensified Algebra—that combines core algebra content with insights from research on how students learn mathematics and explicit noncognitive supports focused on key attitudes, beliefs, and behaviors essential to student success. The results of the study show that, when implemented with fidelity, participation in the program significantly increased student achievement on the state end-of-course algebra I assessment.     

Effect of a randomised 12-week resistance training programme on muscular strength,cross-sectional area and muscle quality in women having undergone Roux-en-Y gastric bypass

The purpose of this study was to examine the effect of a 12-week resistance training programme on fat-free mass (FFM), muscle cross-sectional area, muscular strength and muscle quality in women who underwent Roux-en-Y gastric bypass surgery. Participants were 16 women (mean age = 44.9 ± 10.2 years) from bariatric surgical groups who were randomly assigned into either a control or an intervention group. Air displacement plethysmography measured FFM and magnetic resonance imaging measured quadriceps muscle cross-sectional area and whole thigh muscle cross-sectional area. Muscular strength and quality was assessed using an estimated 1-Repetition Maximum assessment. All measurements were collected twice, at baseline and at a 12-week follow-up. There were significantly greater improvements in leg press strength (mean differences = 55.4%, P < 0.001, Cohen’s d = 2.4), leg extension strength (mean differences = 18.0%, P = 0.014, Cohen’s d = 0.86) and leg press muscle quality (mean differences = 54.5%, P < 0.001, Cohen’s d = 1.9) in the intervention group compared to the control group following the resistance training programme. The resistance training intervention significantly improved muscular strength and quality; however, it did not illicit changes in FFM or muscle cross-sectional area in women who underwent Roux-en-Y gastric bypass surgery.     

Comment on ‘Ventilation and blood lactate increase exponentially during incremental exercise’ : A reply

Oar force and oar angle data resulting from a 6‐min maximal rowing ergometer test undertaken by novice (n = 9), good (n ‐ 23) and national (n = 9) level male rowers, were used to identify biomechanical performance variables which accurately discriminated between rowers of differing ability levels. The variables included two work capacity measures, mean propulsive power output per kilogram of body mass (W kg^‐1) and propulsive work consistency (%), and two skill variables, stroke‐to‐stroke consistency (%) and stroke smoothness (%). Discriminant function analysis indicated the presence of two functions, both of which clearly indicated the importance of mean propulsive power output per kilogram of body mass as a discriminating variable. Function 2 gave greater weight to stroke‐to‐stroke consistency and stroke smoothness than function 1; however, function 1 was the most powerful discriminator. Classification procedures were used to predict the ability level to which a rower most likely belonged and involved defining the ‘distance’ between each rower and each ability level centroid, with the rower being classified into the ‘nearest’ ability level. These procedures indicated that 100% of the elite, 73.9% of the good, 88.9% of the novice and 82.9% of all rowers were correctly classified into their respective skill levels. Stepwise discriminant analysis included the variables in the following order: mean propulsive power output per kilogram of body mass, stroke‐to‐stroke consistency, stroke smoothness and propulsive work consistency (P < 0.001). The results of this study indicate that biomechanical performance variables related to rowing capacity and skill may be identified and used to discriminate accurately between rowers of differing skill levels, and that, of these variables, propulsive work consistency is the least effective discriminator.     

Physiological Effects of Deep Water Running following a Land-Based Training Program

Abstract

The purpose of this study was to examine differences in knowledge representation and problem solutions in expert and novice youth baseball players. Ninety-four players in two age divisions, 7–8 years of age and 9–10 years of age, were assigned to three levels of expertise: high; average; and low skilled. Each subject participated in an interview session to elicit knowledge representation and solutions to five different defensive game situations. Interviews were transcribed and analyzed for content, solution to the problem, errors in problem solution, and qualitative trends. The frequency of advanced solutions to each of the five situations were analyzed in separate chi-square tests for age and expertise. Differences among the levels of expertise were found for the accuracy of solutions to three complex situations. Age was significant for only one situation. Patterns of knowledge content accessed during advanced and less advanced responses indicated both experts and novices were in a beginning stage of developing baseball knowledge structures. Errors in problem solutions indicated children had difficulty monitoring critical conditions and making correct inferences. Players' and teammates' ability to execute baseball skills seemed to influence the content and structure of tactical knowledge accessed during problem solution.     

Showing How Many: young children's written representation of number

Abstract This paper reports a simple experiment which explores young children's written representation of number. Previous research (e.g. Hughes, 1983; Sinclair, Siegrist & Sinclair, 1982) has shown that several factors may influence the extent to which children will spontaneously deploy their knowledge of numerals to represent numerosity, but the available evidence is insufficient to provide a clear account of the relative weight of these factors. The present experiment involved presenting five to six year‐old children with arrays of simple objects and manipulating the wording of the instructions. The results showed that the use of the term ‘how many’ led the vast majority of the children to show numerosity by using materials. In contrast, when asked to represent ‘what’ they could see, most children concerned themselves with depicting the nature of the objects in the array by drawing or writing. These findings suggest that the linguistic context of the task is important in determining the children's representational strategies. Furthermore, it is argued that children's understanding of number and their ability to use numerals is quite separable from their knowledge of when it is appropriate to deploy these skills.     

Fitting Structural Equation Model Trees and Latent Growth Curve Mixture Models in Longitudinal Designs: The Influence of Model Misspecification

When conducting longitudinal research, the investigation of between-individual differences in patterns of within-individual change can provide important insights. In this article, we use simulation methods to investigate the performance of a model-based exploratory data mining technique—structural equation model trees (SEM trees; Brandmaier, Oertzen, McArdle, & Lindenberger, 2013)—as a tool for detecting population heterogeneity. We use a latent-change score model as a data generation model and manipulate the precision of the information provided by a covariate about the true latent profile as well as other factors, including sample size, under the possible influences of model misspecifications. Simulation results show that, compared with latent growth curve mixture models, SEM trees might be very sensitive to model misspecification in estimating the number of classes. This can be attributed to the lower statistical power in identifying classes, resulting from smaller differences of parameters prescribed by the template model between classes.     

Numerically restricted food intake in the rat in a free-feeding situation

Rats were trained to leave an array of food after they had consumed a fixed number (three, four, or five) of food items. This discrimination remained in effect despite a shift from 45-mg Noyes pellets to larger and irregularly sized sunflower seeds. The present demonstration replicates work first reported 50 years ago by Otto Koehler and his associates (e.g., Marold, 1939; see also Koehler, 1950), who used avian subjects, and, like those studies, it involved both positive and negative social reinforcement. The present procedure provided a rare instance in which numerical control was exerted over behavior that was primarily consummatory in nature. The results are viewed in terms of the wider literature of numerical competence in animals and are discussed in terms of a numerical process known asprotocounting (Davis & P’erusse, 1988b).     

The Community of Practice among Mathematics and Mathematics Education Faculty Members at an Urban Minority Serving Institution in the U.S.

Using narrative inquiry as a research method, four mathematics and mathematics education faculty members explored the integration of theoretical perspectives into their personal narratives as they developed a community of practice. Initially their focus was strictly on improving their students’ mathematical knowledge. As their community of practice matured, however, their work took on a larger meaning as they contributed to the institution’s strategic goal of raising the annual dollar amount of external funding and to the development of their personal and collective identities. This unusual level of inter-departmental collaboration has been recognized by the institution’s highest administrators, who have called upon its members to develop new, collaborative partnerships with regional school districts and community colleges.     

A perinatal intervention program for urban american indians part 1: design, implementation, and outcomes

High infant mortality rates among American Indians are disproportionate to state statistics for other races and higher than the national average. These findings prompted a community health center in a large Midwestern city to create and provide an American Indian infant mortality reduction project in the early 1990s. Strategies for program implementation included networking with local organizations, communicating with reservation health clinics throughout the state, educating American Indian mothers and their community about factors contributing to American Indian infant mortality, and providing individual case management to American Indian women and infants. We offer this article for three reasons: This grant project was successful, disparity in rates of infant mortality among peoples of color continues, and a paucity of information exists about the health behaviors of American Indian women.     

Structuring Occasions

Within the mathematics education literature, the term constructivism has been subject to a diversity of interpretations, many of which are trivializations of original theoretical work. We suggest that trivialized versions of constructivism continue to be promulgated due, in large part,to misunderstandings of some of the vocabulary adopted by its advocates. This situation has been the source of considerable frustration in our ongoing efforts to communicate the insights and implications of radical and social constructivist theories to preservice and practicing teachers. We discuss some of the specifics of these frustrations along with strategies intended to flag and circumvent them in our work with teachers. The writing is structured around a set of recursively elaborated interpretations of a classroom episode. Developed around varied understandings of the terms structure and construct, these interpretations are intended to show how we have worked with teachers to foster a deep appreciation of how learning might be reframed as dependent on, rather than determined by, teaching.This revised version was published online in September 2005 with corrections to the Cover Date.