Shared databases are used for knowledge exchange in groups. Whether a person is willing to contribute knowledge to a shared database presents a social dilemma: Each group member saves time and energy by not contributing any information to the database and by using the database only to retrieve information which was contributed by others. But if…

The conditional intervention principle is a formal principle that relates patterns of interventions and outcomes to causal structure. It is a central assumption of experimental design and the causal Bayes net formalism. Two studies suggest that preschoolers can use the conditional intervention principle to distinguish causal chains, common cause…

Single-case design and progress monitoring methodologies are efficient and cost-effective strategies for increasing accountability for indirect service provision. Single-case design conceptualizes the treatment of an individual as an experimental process that can be monitored over time and evaluated for effectiveness. Increasingly in clinical,…

This article presents a discussion of mixed methods (MM) sampling techniques. MM sampling involves combining well-established qualitative and quantitative techniques in creative ways to answer research questions posed by MM research designs. Several issues germane to MM sampling are presented including the differences between probability and…

Although acquisition criteria are a fundamental issue for SLA research, they have not always been adequately defined or elaborated in the literature. This article critically scrutinizes one such criterion, the emergence criterion, proposing an explicit, operational definition. After discussing emergence as a theoretical construct, the article…

This article outlines the planning towards a research design to learn about leadership as it is constructed, experienced and developed in schools. It is intended that the research would go beyond an individual's account to gain an insight into the relationships and social dynamic within the organization. The hypothesis is that the degree of…

National studies of science education have unanimously concluded that preparing our students for the demands of the 21st century workplace is one of the major goals. This paper describes a study of student activities in introductory college physics labs, which were designed to help students acquire abilities that are valuable in the workplace. In…

This paper outlines the methodological dimensions of the secondary literacy research evaluation that is the focus of this special issue-the New Zealand-based Secondary Schools' Literacy Initiative (SSLI). We argue that these methodological dimensions are an example of the type of contextualised and critical research that might be usefully applied…

Should the Russians be included in the evaluation and, if so, how can that be done? Based on the axiological assumption that the social justice theory of ethics leads to an awareness of the need to redress inequalities by giving precedence, or at least equal weight, to the voice of the least advantaged groups in society who may not have sufficient…

Food and nutrition affect the course in physical development that our bodies will follow. Our emotional make-up and mental behavior may be influenced by diet, but the direct relationship between these aspects of development and nutrition needs further study. A new research approach is described. (Author/RH)

Argues that more attention should be given to the specification of the independent and dependent variables which describe, explain and predict intraindividual stability and change over time. Statistical techniques for such study are briefly discussed. (Author/SDH)

A procedure for testing heterogeneity of variance is developed which generalizes readily to complex, multi-factor experimental designs. Monte Carlo studies indicate that the Z-variance test statistic presented here yields results equivalent to other familiar tests for heterogeneity of variance in simple one-way designs where comparisons are…

The use of multiple regression as a data-analytic tool is examined for the cases of balanced and unbalanced designs. The utility of this method for testing specific contrasts, both orthogonal and nonorthogonal is discussed and some interpretive cautions are examined. (Author)

Designs for sequential sampling procedures that adapt to cumulative information are discussed. A familiar illustration is the play-the-winner rule in which there are two treatments; after a random start, the same treatment is continued as long as each successive subject registers a success. When a failure occurs, the other treatment is used until…