The use of correlation coefficients in test validation

Although the Pearson Product Moment Correlation Coefficient, r, is commonly used in student selection, it is argued here, that it is frequently more appropriate to use the Bi-serial Correlation Coefficient r_bis for this purpose.Now working in Clinical Psychology.     

Effect of glucose polymer ingestion on energy and fluid balance during exercise

Nine male triathletes were studied during 160 min of exercise at 65% VO2 max on two occasions to examine the effect of glucose polymer ingestion on energy and fluid balance. During one trial they received 200 ml of a 10% glucose polymer solution at 20 min intervals during exercise (CHO), while in the other they received an equal volume of a sweet placebo (CON). On average, blood glucose levels (CON = 4.2 +/- 0.2 mmol l-1, CHO = 4.8 +/- 0.1, mean +/- S.E.) and respiratory exchange ratios (CON = 0.84 +/- 0.01, CHO = 0.87 +/- 0.01) during exercise were higher (P less than 0.05) as a result of the glucose polymer ingestion. There were no differences between trials, however, in the estimated plasma volume changes during exercise. Exercise time to exhaustion at an intensity corresponding to 110% VO2 max, performed 5 min after the submaximal exercise, was not influenced by glucose polymer ingestion. Relative to a control exercise bout conducted without prior exercise, however, sprint performance and postexercise blood lactate accumulation were impaired in both trials. It is concluded that glucose polymer ingestion maintains blood glucose levels and a high rate of carbohydrate oxidation during prolonged exercise, without compromising fluid balance.     

Le diagnostic du potentiel d’apprentissage par LPAD: Une etude de la fidélité

The present study was intended to test some of the psychometric properties of Feuerstein’s Learning Potential Assessment Device (LPAD), in particular the reliability of the Set Variations II, considered to assess modificability or learning capacity. Thirty 10-year-old children were studied: an experimental group (N=20) submitted to two training sessions with Set Variations II and a control group (N=10). Both groups were administered three times the Standard Progressive Matrices (SPM). The experimenter’s interventions during training were semi-standardized, based on an examination guide, and the helps given were classified in four types. Analyses dealt with the number and type of helps provided as well as with errors during training. Correlations between these indices for the two sessions of training were rather low, indicating weak stability, in particular with respect to the helps provided. Correlations were also computed between the gains in SPM for the three administrations, indicating low stability in amount of progression. Further, it was also noted that the experimental group did not progress more than the control group. Conclusions are drawn with respect to reliability and validity of the Set Variations Test, as well as, on a more theoretical level, with respect to the concept of cognitive modifiability.     

Child abuse: An operational longitudinal study

A one-year longitudinal study was conducted of the medical, social and legal status of 102 (65%) of 156 abused children identified during 1975. The data revealed that the prognosis is grave with almost half of the sample showing indication of repeated abuse or residual effects of the Initial incident. Most of the abused children were returned to their homes with minimal supervision by an otherwise active Division of Family Service of the State Welfare Agency. Children under three years of age were at higher risk than older patients. Improvement was associated most frequently with separation of the perpetrator and the victim or by receipt of appropriate supportive measures. The data emphasize the therapeutic importance of interagency and Interprofessional communication and cooperation.Since the syndrome of the battered child was established,^(1,2) considerable advances have been made in the diagnosis, treatment and protection of the abused children.(3) The prognosis is still grave. A retrospective study showed that the majority of the abused children were developmentally retarded⁽⁴⁾ and a prospective study confirmed this finding.⁽⁵⁾Those seeking to promote the welfare of the identified abused child are confronted with severely limited therapeutics alternative, a grave prognosis and a paucity of data to guide them in their decisions.The present one-year longitudinal study of abused children seen during 1975 at Cardinal Glennon Memorial Hospital for Children was undertaken with the goal of providing Information on the current system of managing the Identified abused child.     

Generic gold standard or contextualised public good? Teaching excellence awards in post-colonial South Africa

ABSTRACT

Teaching Excellence Awards have raised the profile of teaching as a scholarly project. There are however a number of questions about what constitutes teaching excellence and how ‘excellence’ is understood in current higher education. In a post-colonial South Africa, where significant injustices permeate our society, we question whether excellence can be understood in a generic manner. Furthermore, we argue that as universities are a public good, teaching excellence needs to explicitly attend to the ways in which universities contribute to broad goals of transformation and inclusivity. We analysed data from the national Teaching Excellence Awards and 13 South African universities’ awards to interrogate the discourses that underpin ‘excellence’ in this context of social inequality. We found that while the awards have gone some way to enhancing the position of teaching in institutions, ‘excellence’ was largely articulated in fairly generic ways which failed to take into account the enablements and constraints of the discipline and the institution. Furthermore, the guidelines and criteria privilege a decontextualised notion of excellence that seeks a ‘gold standard’ and validates performativity, rather than a contextualised response to the needs of the students.     

Association of group learning with mathematics achievement and mathematics attitude among eighth-grade students in the US

This study examined a large, nationally-representative sample of eighth-grade students in the US to assess how the frequency of group learning activity in mathematics classrooms was associated with mathematics achievement and three measures of attitudes toward mathematics. Results showed that moderate amounts of group work in class had positive effects on mathematics achievement scores. Moreover, a significant interactive effect was evident, with girls showing greater achievement benefits from group work than boys. Increased levels of group work were also associated with more positive attitudes toward mathematics.