An Empirical Bayes Approach to Mantel-Haenszel DIF Analysis

We developed an empirical Bayes (EB) enhancement to Mantel-Haenszel (MH) DIF analysis in which we assume that the MH statistics are normally distributed and that the prior distribution of underlying DIF parameters is also normal. We use the posterior distribution of DIF parameters to make inferences about the item's true DIF status and the posterior predictive distribution to predict the item's future observed status. DIF status is expressed in terms of the probabilities associated with each of the five DIF levels defined by the ETS classification system: C–, B–, A, B+, and C+. The EB methods yield more stable DIF estimates than do conventional methods, especially in small samples, which is advantageous in computer-adaptive testing. The EB approach may also convey information about DIF stability in a more useful way by representing the state of knowledge about an item's DIF status as probabilistic.     

Models and Morals: Meanings underpinning the scientific study of special educational needs

This paper discusses and evaluates four different approaches used by the writer and several other researchers to study special educational needs. The first approach, the Difference Model, is seen as poorly suited to addressing both a continuum of special educational needs and motivational issues integral to these needs. The second approach, the Developmental Model, discusses work within a Vygotskian paradigm, and offers important information on the human mediation needed to enhance learning. The third approach, the Ecological Model, highlights contextual factors and the child's perspective, as expounded within Bronfenbrenner's theory. It encourages an understanding of the wider cultural and socio-economic factors impinging on special educational needs. Finally, the fourth approach, the Discursive Model, emphasises a collaborative development of meanings and is valuable in the adoption of a partnership approach towards special educational needs. The evaluation of these differing approaches suggests the wisdom of adopting a multiple approach to the study of special educational needs.     

Enabling teachers to become pedagogical leaders: case studies of two IDEAS schools in Singapore and Australia

This research paper is about the role of the principal in enabling teacher leadership for pedagogical innovations and school improvement studied in two Innovative Designs for Enhancing Achievements in Schools (IDEAS) schools in Singapore and Australia over a 3-year period from 2005 to 2007. The research reported is based on the developing relationship between principals and teacher leaders as they collaboratively engage in a process of whole school improvement. Both case study schools used the IDEAS school improvement program which originates from the Leadership Research Institute, University of Southern Queensland. The cases trace the facilitation of the IDEAS process in each school and highlights the centrality of teacher leadership in bringing about change in school-wide pedagogy and a process of school re-culturing. It underlines the fact that principals need to support the enabling of leadership among teachers by giving them the space, time and responsibility to make decisions about curriculum work and ensuring that these are aligned with new organizational structures and processes. The paper discusses how the schools were different and yet similar in many ways between the two countries, Singapore and Australia, with regard to the nature of the enabling processes for organizational revitalization and school capacity building. It draws out some implications for school leadership and school improvement.