Students' and pre-service teachers' conceptions of scientists have been assessed in a variety of studies. One of the most commonly used instruments is the Draw-A-Scientist Test (DAST) which offers the advantage that no verbal skills are needed by the participants. In some studies, methodical challenges related to the DAST have been discussed; for…

Scientific reasoning competencies are relevant science competencies and therefore the development of assessment instruments for scientific reasoning competencies has become an integral part of science education research. However, some authors have questioned the validity of the instruments available so far, since their psychometric quality has not…

This study evaluates a 12-item instrument for subjective measurement of mental load (ML) and mental effort (ME) by analysing different sources of validity evidence. The findings of an expert judgement (N = 8) provide "evidence based on test content" that the formulation of the items corresponds to the meaning of ML and ME. An empirical…