Accurate teacher judgements can enhance pupils' learning about science and technology. This study explored primary school teachers' judgements about their pupils' ability to reconstruct an electrical and a mechanical system. The judgement accuracy of most teachers was poor, gender-biased, and underestimation was more common than overestimation. The teachers’ gender or self-efficacy beliefs do not seem to affect their judgement accuracy, whereas greater technical knowledge and teaching experience might be beneficial. The teachers’ judgements were primarily based on their estimation of pupils’ cognitive abilities and learning behaviour, which both had less bearing on pupils’ performance than the teachers had expected. Diagnostic tasks for technical abilities, like the ones used in this study, can be used by primary school teachers working with children aged nine and above to calibrate their judgement accuracy and adapt their teaching to their pupils’ varying levels of prior knowledge. Pupils’ performance on these non-verbal tasks can reveal unexpected abilities.

Pupils benefit from adaptive instruction and feedback from their teachers. A prerequisite for providing adaptive instruction is that teachers’ diagnostic ability enables them to correctly perceive their pupils’ skill level. A short course has been developed to improve primary school teachers’ diagnostic ability for engineering. Based on Nickerson’s anchoring and adjustment model, the participants became aware of the differences their own and pupils’ use of information when constructing technical systems. The Fischer scale was used as a model to understand and identify pupils’ development in using such information. The participants were given examples of pupils’ reconstructions of technical systems. They were asked to evaluate these work products in four ways: relative and absolute, combined with intuitive and explicit. The results reveal that relative and absolute diagnoses can differ considerably for the same teacher and between teachers, depending on whether they are implicit or explicit. Post-test results show that the course improved the ability to explain the differences between pupils’ use of information to construct a technical system. The course also had a strong, significant, positive impact on teachers’ self-efficacy beliefs about technology education.

This study aimed to develop and validate, based on the Evidence Centered Design approach, a generic tool to diagnose primary education pupils’ prior knowledge of technological systems in primary school classrooms. Two technological devices, namely the Buzz Wire device and the Stairs Marble Track, were selected to investigate whether theoretical underpinnings could be backed by empirical evidence. Study 1 indicated that the tool enabled pupils to demonstrate different aspects of their prior knowledge about a technological system by a wide variety of work products. Study 2 indicated that these work products could be reliably ranked from low to high functionality by technology education experts. Their rank order matched the Fischer-scale-based scoring rules, designed in cooperation with experts in skill development. The solution patterns fit the extended non-parametric Rasch model, confirming that the task can reveal differences in pupils’ prior knowledge on a one-dimensional scale. Test–retest reliability was satisfactory. Study 3 indicated that the diagnostic tool was able to capture the range of prior knowledge levels that could be expected of 10 to 12 years old pupils. It also indicated that pupils’ scores on standardised reading comprehension and mathematics test had a low predictive value for the outcomes of the diagnostic tool. Overall, the findings substantiate the claim that pupils’ prior knowledge of technological systems can be diagnosed properly with the developed tool, which may support teachers in decisions for their technology lessons about content, instruction and support.