Within professional education (and in dental education particularly) the notion of the spiral curriculum still has considerable influence on curriculum design. The spiral is conceived as consisting of two parallel strands (theory and practice) which develop hand in hand as the student progresses through the curriculum. However, Illeris (1999: 151) has pointed out that "spiral models have the disadvantage that they indicate a 'smooth', evenly progressive sequence - in contrast to the uneven sequence of reality with jumps in learning". An additional problem in dental education is that the two strands of the spiral develop in very different ways: the conceptual development of the clinical science has the potential to be ordered to support a systematic development in student understanding, but the experiential development is much less predictable as students have to tackle the issues presented by patients in a much less structured fashion. There is, therefore the potential for the two strands of the spiral curriculum to be disengaged from each other.
It has been suggested by Kinchin et al (2011) that one of the functions of threshold concepts in dental education may be to integrate the conceptual and experiential strands of the curriculum. However, this is made much more difficult if the two strands are developing independently of each other. This then raises a question about the distribution of threshold concepts in the dental curriculum and whether they can be delivered in a planned sequence at all.
Discussion is offered of the possible positioning of thresholds within a spiral curriculum, and the consequences for teaching and professional learning.
Illeris, K. (1999) How we learn: Learning and non-learning in school and beyond. London, Routledge.
Kinchin, I.M., Cabot, L.B., Kobus, M. and Woolford, M. (2011) Threshold concepts in dental education. European Journal of Dental Education, In Press.