A Note on Non-parallelism of Pretest and Posttest Measures in Assessing Change

In the study of differences, change, or growth, pretest and posttest measures often cannot be considered to be “parallel” in the usual test-theory sense. Empirical data supporting this conclusion is presented. But under this condition of non-parallelism of pretest and posttest measures, it is possible for change scores to be more reliable and more valid than ordinarily believed by most psychometricians.     

Improving Adult Learning Programs

This paper analyses the process of secondary school admission in the District of Thanet in the contexts of consumerism and the functioning of the educational marketplace. It examines tensions between consumers and producers, and juxtaposes educational need with individual gain, arguing that the Local Education Authority's policies, the plethora of admission procedures and the superordinate political positioning of the market over need combine to reinforce educational exclusion. The paper concludes that consumerism strengthens the social advantages enjoyed by some individuals, but does not efficiently meet educational needs or effect equitable access to school places.     

Quantification of maximal power output in well-trained cyclists

ABSTRACT

This study aimed to compare mechanical variables derived from torque-cadence and power-cadence profiles established from different cycle ergometer modes (isoinertial and isokinetic) and modelling procedures (second- and third-order polynomials), whilst employing a novel method to validate the theoretical maximal power output (P_max). Nineteen well-trained cyclists (n = 12 males) completed two experimental sessions comprising six, 6-s maximal isoinertial or isokinetic cycling sprints. Maximal pedal strokes were extracted to construct power–cadence relationships using second- and third-order polynomials. A 6-s sprint at the optimal cadence (F_opt) or optimal resistance (T_opt) was performed to assess construct validity of P_max. No differences were found in the mechanical parameters when derived from isokinetic (P_max = 1311 ± 415, F_opt = 118 ± 12) or isoinertial modes (P_max = 1320 ± 421, F_opt = 116 ± 19). However, R² improved (P < 0.02) when derived from isoinertial sprints. Third-order polynomial modelling improved goodness of fit values (Standard Error, adjusted R²), but derived similar mechanical parameters. Finally, peak power output during the optimised sprint did not significantly differ from the theoretical P_max in both cycling modes, thus providing construct validity. The most accurate P-C profile can be derived from isoinertial cycling sprints, modelled using third-order polynomial equations.     

The Development of Affiliative and Agonistic Social Patterns in Differentially Reared Monkeys

Bonnet macaques that had been reared from 3 to 6 months of age in experimental environments that appeared to adversely affect their ability to separate from mother to explore a novel physical environment in dyadic assessments shortly after the rearing experience were tested during late adolescence, an average of 2.5 years later, under conditions of increasing unfamiliarity and complexity of the social milieu. 6 monkeys, the low-foraging-demand (LFD) group, were reared by mothers having constant easy access to food during the experimental rearing period. Another 6 monkeys, the variable-foraging-demand (VFD) group, were reared by mothers having a foraging task that varied between easy and difficult in 2-week blocks during the experimental rearing period. Although no treatment group differences were evident during the initial rearing period, during subsequent social challenges VFD monkeys exhibited a diminished capacity for affiliative social engagement relative to LFD monkeys and were socially subordinate to LFD monkeys.     

The combined effects of dosage level and interstimulus interval on the formation of one-trial poison-based aversions in rats

Adult male rats were allowed to drink a novel solution of sodium saccharin which was followed .5, 1.5, 4.5, 7.0, 13.5, or 24.0 h later by intubation of a .9, 2.7, 8.1, or 12.15% (w/v) solution of sodium chloride (NaCl). Three days after the single training trial, consumption of saccharin was again measured. Significant differences between groups were found. When consumption by the experimental groups at each CS-UCS delay was compared with that of the isotonic NaCl (.9%) control group, it was found that all groups showed aversions at delays of .5, 1.5, and 4.5 h. Animals intubated with 8.1% or 12.15% NaCl solution also showed aversions at a delay of 7.0 h, and those intubated with the 12.15% solution showed an aversion at a delay of 13.5 h. No NaCl concentration used produced aversions at a CS-UCS interval of 24.0. These results reflect differences in the effectiveness of a range of NaCl concentrations in producing one-trial aversions at long CS-UCS intervals.     

Correction to: College Costs and Credit Cards: How Student Credit Card Use Influences College Degree Attainment

Research in Higher Education - The original version of this article unfortunately contained a mistake. The corrected details are given below.