Avoiding common assessment pitfalls

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This case study was written by Matthew Benyohai, Head of Physics at a secondary school. As you read this case study, reflect on how the teacher considers the validity and reliability of their assessment approaches. Take some time to think about what the teacher does, how they do it, what they might do differently and how this might influence your own practice. Two important qualities of assessments are validity and reliability. Validity is a measure of how well an assessment reflects what you want to assess (Issacs et al. 2013) or how well an assessment supports the inferences we make from the results (Messick 1989). Reliability is a measure of how consistent the results of, or inferences from, an assessment are (Isaacs et al. 2013). These two concepts are often in competition with one another (Harlen 2005). If I try to make an assessment more reliable, by introducing lots of multiple-choice questions, I’d be reducing the validity (Wiliam 1993). If I were to use an open investigatio

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This Post Has 2 Comments

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    Angela Murphy

    Provides great clarity for the terms validity and reliability in relation to assessment. It is really important for ECT to understand the difference and how we use formative and summative assessment processes to secure both reliability and validity over time.

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