High-quality Assessments Research Articles

Seeking a rational approach to setting conservation priorities for marine mammals

The U.S. Endangered Species Act establishes categories for endangered and threatened species but provides no criteria for deciding when a species should be listed, delisted, or downlisted. As a result, listing and recovery actions for marine mammals are widely inconsistent. In most cases, Endangered Species Act listing and recovery actions have been done without the benefit of high-quality population assessments and have been based on arbitrary, nonquantitative criteria. A new approach to determining classification criteria for marine mammals is presented, with the North Pacific humpback whale as a test case. The key idea underlying this approach is an attempt to incorporate biological uncertainty explicitly in the definition of threatened and endangered. I sketch the essential ingredients of this new approach and its motivation and use this discussion to illuminate the challenges we face in pursuing conservation in an uncertain and data-poor world.

Review and performance of four models to assess the fate of radionuclides and heavy metals in surface soil

The nuclear industry uses computer models to calculate and assess the impact of its present and future releases to the environment, both from operating reactors and from existing licensed and planned waste management facilities. We review four soil models varying in complexity that could be useful for environmental impact assessment. The goal of this comparison is to direct the combined use of these models in order to preserve simplicity, yet increase the rigor of Canadian environmental assessment calculations involving soil transport pathways. The four models chosen are: the Soil Chemical Exchange and Migration of Radionuclides (SCEMR1) model; the Baes and Sharp/Preclosure PREAC soil model, both used in Canada's nuclear fuel waste management program; the Convection-Dispersion Equation (CDE) model, commonly used in contaminant transport applications; and the Canadian Standards Association (CSA) derived release limit model used for normal operations at nuclear facilities. We discuss how each model operates, its timestep and depth increment options and the limitations of each of the models. Major model assumptions are discussed and the performance of these models is compared quantitatively for a scenario involving surface deposition or irrigation. A sensitivity analysis of the CDE model illustrates the influence of the important model parameters: the amount of infiltrating water, V; the hydrodynamic dispersion coefficient, D; and the soil retention or partition coefficient, Kd. The important parameters in the other models are also identified. This work shows we need tested, robust, mechanistic unsaturated soil models with easily understood and measurable inputs, including data for the sensitive or important model parameters for Canada's priority contaminants. Soil scientists need to assist industry and its regulators by recommending a selection of models and supporting them with the provision of validation data to ensure high-quality environmental risk assessments are carried out in Canada. Key words: Soil transport models, environmental impact assessments, model structure, complexity and performance, radionuclides 137Cs, 90Sr, 129I

Fostering deep and active learning through assessment

Pressures on the unit of resources within higher education are noted and the possible implications for assessment practice considered. There is a tension between low-cost and high-quality assessments, yet assessment appears to drive the students' agenda and requires careful thought if the programme design is to lead to high-quality learning outcomes. A theoretical framework is presented with the purpose of developing an assessment strategy which will enhance the quality of learning by the student. A case study of an introductory accounting module is described and issues of teaching, learning and assessment are explored. A message of hope is signalled; it may be possible to foster deep learning through assessments which engage the student actively with the subject, despite the apparent constraints acting upon academics.

Introduction: Policy and Validity Prospects for Performance-Based Assessment

High interest in performance-based assessment of educational achievement is indicated by recent conferences, special journal issues, and national television coverage. The president's and governors' educational goals reflect the central role of assessment in reform. A prominent view is that changes in assessment, using more complex, meaningful, and integrative performance tasks, will improve education. New assessments present challenges to the curriculum, teaching practices, and presentation of student achievement information to policymakers and to the public. Sufficient high-quality assessments must be available before their impact on educational reform can be assessed. Although interest in performance-based assessment is high, our knowledge about its quality is low. Moreover, few psychometric templates exist to guide the technical practices of assessment developers.

Do occupation-related physical factors contribute to arthritis?

Occupational physical activities over many years can induce osteoarthritis in selected joints. Well-studied examples include evidence of osteoarthritis of the knees and spine in miners, osteoarthritis of the hip in farmers and increased rates of osteoarthritis of otherwise not usually affected upper extremity joints in pneumatic drill operators. Occupation-induced osteoarthritis may not be limited to these uncommon occupations but may, in fact, account for a large proportion of osteoarthritis in the population. Additional studies of this issue, which incorporate high-quality ergonomic assessments of occupational physical activities, are needed. People with pre-existing arthritis often experience work disability, especially when faced with physically demanding jobs in which they have little control over the pace or the specific physical demands of their labour.