In this series of posts I record my notes from Daisy Christodolou’s book “Making good progress? The future of Assessment for Learning” It is quite excellent. You can buy a copy here.
Exams based on the difficulty model produce a lot of information that can potentially be used formatively as pupil performance on each question can be measured using the principle of question-level or gap analysis.
In the quality model of exam what looks like an exam is still an assessment that relies heavily on descriptors.
Exams sample a domain however and are not direct measurements. While a test that samples from a domain may allow inferences about the domain but it does not allow inferences about the sub-domains because the number of questions for each sub-domain will be too small. The resolution is too granular and not fine enough. Careful analysis of the question responses may provide useful feedback, particularly for harder questions that rely on knowledge from multiple domains, but this more nuanced information is not captured in a question-level analysis.
Harder questions at GCSE rely on knowledge of several concepts. It is hard to formative assess where student misconceptions lie if they get these questions wrong from a gap analysis. Complexity reduces formative utility.
It is not possible to measure progress fairly using summative exams [like past GCSE papers] because it is entirely possible for a student to have made significant progress on a sub domain but for that to not show up in a summative exam situation and because that topic may be poorly represented in the test, you cannot use just those questions to analyse their progress either.
The risk is that teachers may be incentivised to focus on activities which improve short term performance but not long term learning. Measuring progress with grades encourages teaching to the test which compromises learning.
Because exam boards spend so much time and resources trailing and modelling assessments it is hopeless for teachers to think they can match that rigour in the assessments they design.
Often tests are pulled in two different directions and this highlights a tension between classroom teachers who want formative data and senior managers who want summative progress data.