Drawing has been used to assess many aspects of human development and conceptions for over a century. In 2001, Thomas, Pedersen and Finson offered the scientific community a test based on drawing to assess conceptions of teaching. This test has been widely used since. Two decades after the publication, social contexts and paradigms of teaching and learning have changed in many ways. Moreover, the cultural factor is important in the usability of such a tool. Therefore, after questioning the scoring rubric for the Thomas et al. (2001) test, the test has been modified to reflect what happens in a science classroom today in Western Switzerland, in terms of teaching and learning, thus shedding light on the teachers’ conceptions. The aim of this thesis is to propose a thoroughly reviewed version of the initial drawing test, accompanied by companion tasks. The test provides the researcher with an overview of how the participant relates to their 'ideal' of teaching, via the companion tasks, and what are the unconscious conceptions of teaching preservice teachers hold, via the drawing test. The test has been administered to Biology and Physics preservice teachers at the Lausanne Teacher University, (HEP-VD, Lausanne, Switzerland), during one term of Didactics tuition, and cross-checked by a professor. The results show that the modifications made to the original test are reliable, provide relevant information, and allow the assessment of the evolution of conceptions and professionalisation of pre-service teachers. Moreover, the tool proved to be a valuable asset in choosing focus-groups to analyse in a large population.