Threshold Concepts; what we don't yet know

The idea of threshold concepts (TCs) is not a formal theory; it is more of a device to help us think about how learning works. So TCs don't �exist� out there. And so when we claim that they have certain attributes, such as being irreversible, we are making no greater claim than that they appear to do so, and perhaps that we are incorporating this attribute into a definition, so that we can use terms more precisely. There is no particular reason why TCs should be irreversible, and indeed we are not sure whether they �really� are...

So we don't know whether every subject area or discipline has threshold concepts.

We don't know just how much they are features of the body of knowledge itself, or of the learner who is studying it. Clearly they are much more firmly grounded in the object of study than, for example, �learning styles� which are claimed to be properties of the student; but the troublesomeness of knowledge may well be greater for some students than for others.

We don't know whether they are always �desirable� or not. The fact that something functions as a threshold concept, that is helps organise existing knowledge, that it illuminates the path ahead, and so on does not mean that it is �true�. It may well merely be useful. For years, mythology has served as a set of threshold concepts (cf. Armstrong, 2006); myths have explained the place of people in the universe, the origins of all things, what is required and what forbidden, clean and unclean, who can marry whom, and when crops should be planted... For better or for worse, of course, they have no reasonable basis for purporting to explain all this.

So the fact that something is a threshold concept does not make it true. Still less does it make it good; it may be pernicious and/or paranoid. Indeed, one might well argue that all successful evil ideologies have to have at their heart some threshold concepts which enshrine the transformative ideas which enable them to gain converts.

Nor are threshold concepts necessarily powerful. Indeed, we have seen that even when exposed to them, some students do not �get� them. We have seen that the knowledge they embody can be troublesome and easily resisted. And even the student crossing the threshold may well persist in a state of liminality.

There are many more questions than answers, and that�s what makes it all fun!