In summer 2006 the UK Geography, Earth and Environmental Sciences (GEES) Subject Centre held its annual meeting with the theme of Threshold Concepts and Troublesome Knowledge. Following the publication in December of a Special Edition of the GEES publication ‘Planet’ Helen King was contacted by Professor Erik Meyer (
Since then there has been a constant exchange of emails between the three of us exploring some of the ideas around threshold concepts, but also throwing up a lot of questions. So, following is an attempt to briefly summarise the main threads of the discussion that has been taking place since the beginning of 2007 between Helen, Julie and myself in relation to threshold concepts in the geosciences. In the interests of keeping this post a manageable size (and hopefully not boring people!) we’ve tried to keep detail to a minimum, but would be happy to expand and elaborate on any point that anyone would like to pick up on.
The main thread of our discussion has focused on what constitutes a threshold concept in geology, and this is the main area that we are keen to start exploring more widely. Julie started off by suggesting that major scientific concepts like DENSITY might actually be threshold concepts in geology, because once a student really understands density then lots of geological processes are suddenly very easy to understand, e.g. SUBDUCTION. We then started to think about whether RATES or SCALE of geological processes, rather than specific phenomena, might be threshold concepts (incorporating concepts such as DEEP TIME and THINKING IN 3-DIMENSIONS). However, having subsequently struggled (and failed!) to identify a suitable example for our paper we decided it might be better to just open up the debate!
Another line of discussion concerns the fact that threshold concepts are not uniquely defined, so it’s often difficult to articulate exactly why we think something is or isn’t a threshold concept. So is something missing from the definition (i.e. that they are transformative, integrative, irreversible, bounded, and frequently troublesome), or is it the nature of threshold concepts that they are changing and personal, rather than universal and unchanging? And what makes something a threshold concept rather than simply ‘difficult’? Helen’s previous post also raises the interesting question of whether threshold concepts are purely cognitive, or whether they can also be based in behaviour, i.e. practical skills.
We’re also interested in the link between threshold concepts and becoming a geoscientist, i.e. does crossing those conceptual thresholds form part of the journey that a student makes from being a novice to becoming an expert? If so, what happens if they don’t actually acquire the understanding necessary to cross the threshold – can they still become an expert geoscientist? Does it matter?? And are we conscious of crossing a conceptual threshold, or is it only when we recognise the transformation in ourselves, in terms of our thinking and practicing, that we know that it’s been crossed – i.e. we’re conscious of the product, but not necessarily the process? Helen makes a really interesting analogy between being the ‘liminal space’ – the limbo state where a student neither understands nor not understands – and ‘Schrodinger’s Cat’!Finally, how can threshold concepts help us to ‘define’ what is geology and what is, say, geography or environmental science? The boundaries between these disciplines are often very blurred, and the difference between being a geographer or a geologist may come down to the way that somebody thinks and practices (threshold concepts), rather than their stock of knowledge (core concepts).