Equivalence of Population Variances: Synchronizing the Objective and Analysis

Researchers are often interested in establishing equivalence of population variances. Traditional difference-based procedures are appropriate to answer questions about differences in some statistic (e.g., variances, etc.). However, if a researcher is interested in evaluating the equivalence of population variances, it is more appropriate to use a procedure designed to determine equivalence. A simulation study was used to compare novel equivalence-based tests to traditional variance homogeneity tests under common data conditions. Results demonstrated that traditional difference-based tests assess equality of variances from the wrong perspective and that the proposed Levene-Wellek-Welch test for equivalence of group variances the best performing test for detecting equivalence. An R function is provided in order to facilitate use of this test for equivalence of population variances.     

Testgütekriterien der „Profilanalyse nach Grießhaber“. Evaluation eines Verfahrens zur Erfassung grammatischer Fähigkeiten von ein- und mehrsprachigen Grundschulkindern

A diagnostic goal of the “Profile analysis according to Grießhaber” is the assessment of the grammatical ability to place verbs in German sentences in the correct syntactical position. To evaluate the test quality for the first time, 403 monolingual and multilingual primary school children were randomly assigned to three different test materials: Test material that specifically stimulated the target competence led to the best test results. This indicates a low objectivity of application. In addition, ceiling effects for primary school children were detected, which means that the profile analysis can only slightly differentiate among the grammatical abilities of the children. Retest reliability and objectivity of analysis are also too small. In summary, the test quality of the assessment tool should be improved with respect to all of the test quality criteria considered. Hence, we recommend standardizing the profile analysis better and adding more sensitive diagnostic criteria for primary school aged children. Other aspects of profile analysis, for example the improvement of diagnostic competencies of teachers, are recommended for future research.     

Education and Development: A Developing Theme

The following article is based on an analysis of selected examples from the approximately 2500 main articles that have been published in the International Review of Education (IRE) since its inception in 1931 until the fall of 2001. The scope of the topic is education within developing countries and the promotion of such education by industrialised countries and development agencies. After an introduction on the growth of the concern over education and development over seven decades of the journal, three themes are looked at in some more detail: (1) The discussion on nationalism versus internationalism in education, a theme that bears clear relevance to the field "Education and Development" and has been with the journal from its inception but on which one finds more emphasis in the earlier volumes. (2) The language of instruction in developing countries. This theme has also been with the journal from its inception and it is still much debated. (3) The effects of external aid on the education sector in developing countries. Though massive economic aid in the form of grants or loans to the education sector in developing countries is of more recent nature external influence on the education sector has been there since colonial times.     

Influence of using challenging tasks in biology classrooms on students’ cognitive knowledge structure: an empirical video study

Empirical analysis of secondary biology classrooms revealed that, on average, 68% of teaching time in Germany revolved around processing tasks. Quality of instruction can thus be assessed by analyzing the quality of tasks used in classroom discourse. This quasi-experimental study analyzed how teachers used tasks in 38 videotaped biology lessons pertaining to the topic ‘blood and circulatory system’. Two fundamental characteristics used to analyze tasks include: (1) required cognitive level of processing (e.g. low level information processing: repetiition, summary, define, classify and high level information processing: interpret-analyze data, formulate hypothesis, etc.) and (2) complexity of task content (e.g. if tasks require use of factual, linking or concept level content). Additionally, students’ cognitive knowledge structure about the topic ‘blood and circulatory system’ was measured using student-drawn concept maps (N?=?970 students). Finally, linear multilevel models were created with high-level cognitive processing tasks and higher content complexity tasks as class-level predictors and students’ prior knowledge, students’ interest in biology, and students’ interest in biology activities as control covariates. Results showed a positive influence of high-level cognitive processing tasks (β?=?0.07; p?.01) on students’ cognitive knowledge structure. However, there was no observed effect of higher content complexity tasks on students’ cognitive knowledge structure. Presented findings encourage the use of high-level cognitive processing tasks in biology instruction.     

The Influence of Occupational Self-Efficacy on the Relationship of Leadership Behavior and Preparedness for Occupational Change

A theoretical framework for the relationship between preparedness for occupational change, occupational self-efficacy, and leadership is presented. Preparedness for occupational change is defined as the wish to acquire higher task demands (i.e. greater complexity) in the sense that employees have thought about change but have not yet acted to seek change. It explained why preparedness for occupational change is central prior to, during, and after organizational change is introduced. A model of determinants of preparedness for occupational change is established. The application of this model in different stages of organizational change is demonstrated. Central aspects in this model are self-efficacy and leadership. Self-efficacy influences preparedness for occupational change in the different stages. This effect is demonstrated using the three assumed outcomes of self-efficacy (i.e., initiation of behavior, persistence, and effort) and their relationship to preparedness for occupational change. It is assumed that perceived leadership influences occupational self-efficacy. Three factors influencing self-efficacy (mastery experience, vicarious learning, and verbal persuasion) are regarded as possibly being responsible for this effect. The implications of the model for organizational practice are discussed.     

How temporal and spatial aspects of presenting visualizations affect learning about locomotion patterns

Two studies investigated the effectiveness of dynamic and static visualizations for a perceptual learning task (locomotion pattern classification). In Study 1, seventy-five students viewed either dynamic, static-sequential, or static-simultaneous visualizations. For tasks of intermediate difficulty, dynamic visualizations led to better classification performance than static-sequential visualizations, but not than static-simultaneous visualizations. To test whether the temporal aspects of presenting static-simultaneous visualizations (i.e., their permanent visibility) or their spatial aspects (i.e., their arrangement in rows) accounted for this effect, Study 2 investigated three additional static-simultaneous conditions. Seventy-five students viewed static-simultaneous visualizations presented either in columns, matrices, or circles. For tasks of intermediate difficulty dynamic visualizations outperformed pictures presented in columns, matrices, and circles, but not the rows format. Accordingly, for learning about locomotion patterns, dynamic visualizations are better suited than most, but not all static visualization formats. From a practical point of view, effort should be invested into the design of static-simultaneous visualizations to further optimize instructional materials.     

Peer victimization, poor academic achievement, and the link between childhood externalizing and internalizing problems

This study explored whether early elementary school aged children’s externalizing problems impede academic functioning and foster negative social experiences such as peer victimization, thereby making these children vulnerable for developing internalizing problems and possibly increasing their externalizing problems. It also explored whether early internalizing problems contributed to an increase in externalizing problems. The study examined 1,558 Canadian children from ages 6 to 8 years. Externalizing and internalizing problems, peer victimization, and school achievement were assessed annually. Externalizing problems lead to academic underachievement and experiences of peer victimization. Academic underachievement and peer victimization, in turn, predicted increases in internalizing problems and in externalizing problems. These pathways applied equally to boys and girls. No links from internalizing to externalizing problems were found.