Home again: effects of the Mother-Child Home Program on mother and child

4 successive cohorts of low-income families were randomly assigned either to a home-based intervention program that focused on modeling verbal interaction between mother and child around selected toys and books or to comparison treatments. Large program effects were found on maternal interaction styles in videotaped observations. Small IQ and program-specific effects were found for children in contrast to much larger IQ effects found in earlier research. IQ effects did not appear to have been mediated by changes in maternal behavior. A variation in which toys and books were supplied without home visits was as effective as the full program on IQ but not on maternal behavior. 3 years postprogram , there were no detectable effects in achievement or IQ tests or in first grade teachers' ratings of school adjustment and performance, but IQ and achievement scores were near national norms. Reasons for discrepancies with earlier results are discussed. The results highlight the need for continued experimental evaluation of early intervention programs with safeguards to insure that samples are educationally at risk.     

An analysis of different representations for vectors and planes in ℝ3

The purpose of this paper is to present an analysis of the difficulties faced by students when working with different representations of vectors, planes and their intersections in \(\mathbb {R}^{3}\). Duval’s theoretical framework on semiotic representations is used to design a set of evaluating activities, and later to analyze student work. The analysis covers three groups of undergraduate students taking introductory courses in linear algebra. Different types of treatments and conversions are required to solve the activities. One important result shows that, once students choose a register to solve a task, they seldom make transformations between different registers, even though this facilitates solving the task at hand. Identifying these difficulties for particular transformations may help teachers design specific activities to promote students cognitive flexibility between representation registers.     

Refining Students’ Explanations of an Unfamiliar Physical Phenomenon-Microscopic Friction

Research in Science Education - The first phase of this multiphase study involves modeling of college students’ thinking of friction at the microscopic level. Diagnostic interviews were...     

Can sit-to-stand muscle power explain the ability to perform functional tasks in adults with severe obesity?

This study examined the relationship between sit-to-stand (STS) power and physical function in adults with severe obesity. Thirty-eight adults (age: 44 ± 12 years; body mass index [BMI]: 45.2 ± 7.8 kg/m²) completed evaluations of STS power, strength and functional performance. STS power was measured with a wearable inertial sensor, strength was assessed with the isometric mid-thigh pull, and function was measured with the timed up-and-go (TUG), six-minute walk test (6MWT) and 30-s chair STS. Power and strength (normalised to body mass) entered regression models in addition to age, gender, BMI and physical activity (daily step count). Power displayed large univariate associations with TUG (r = 0.50) and 30-s chair STS (r = 0.67), and a moderate association with 6MWT (r = 0.49). Forward stepwise regression revealed that power independently contributed to TUG (β = ?0.40, p = 0.010), 30-s chair STS (β = 0.67, p < 0.001) and 6MWT performance (β = 0.27, p = 0.007). Power also appeared to be a superior determinant of function compared with strength. Power generated via the STS transfer largely underpins the ability to perform functional tasks in adults with severe obesity, although intervention studies are required to investigate a potentially causal relationship.