Balancing the demands of validity and reliability in practice: Case study of a changing system of primary science summative assessment

Abstract

Teacher summative judgements of children’s attainment in science, which are statutory at age 11 in England, require consideration of both valid sampling of the construct and reliable comparison of outcomes. In order to develop understanding of the enacted ‘trade off’ between validity and reliability, this three-year case study, within the Teacher Assessment in Primary Science (TAPS) project, was undertaken during a period of statutory assessment change in England. The case demonstrates an ongoing balancing act between the demands of reliability and validity, and resulted in the development of a teacher assessment seesaw, which provides a model for both interpreting and supporting practice, within and beyond primary science.

Group Moderation Assessment Model: An Example of an Open-Ended Mathematics Exam

“…It is increasingly accepted that the group moderation assessment model can provide teachers with professional learning opportunities in assessment (Adie, 2013;Harlen, 2010;Earle, 2020). Measurement results obtained with open-ended exams contain scoring errors caused by the rater.…”

“…After the workshops held within the scope of the group moderation assessment model, it was found that there were high and consistent relationships between the exam assessments of the raters. The group moderation assessment model can increase the overall consistency by increasing the inter-rater consistency (McNamara, 1996;Earle, 2020). In addition, it has been stated that there is evidence that it can be effective because it eliminates excessive differences in rater rigidity and increases rater consistency by reducing individual biases (Weigle, 1994).…”