Disciplinary knowledge has been described as consisting of a number of “dimensions of variation” (cf. Marton & Booth, 1997), where the variation along each dimension is qualitatively unique. In order for students to holistically experience disciplinary knowledge each of these dimensions of variation need be enacted (i.e. expressed with representations).

We suggest it is possible to construct an idealized pattern of the dimensions of variation that are deemed to be relevant for a given field of knowledge in a given discipline. We call such patterns “idealized patterns of disciplinary relevant aspects,” IPDRA. Each of the dimensions that together constitute an IPDRA can be said to enter discourse in terms of particular configurations, partly prescribed by the “rules” governing the representational format at hand (such as grammar for language). The resultant discursive configurational patterns (cf. Lemke's, 1990, "thematic patterns"; and Tang et al.'s, 2011, "multimodal thematic patterns") can then be compared with the IPDRA to see if the needed dimensions of variation have been enacted.

The specialization of representations to express certain (combinations) of dimensions of variation (what we have called “disciplinary affordances”, see Fredlund, Airey, & Linder, 2012) determines which representations that can do which work in terms of representing the knowledge described by an IPDRA. Thus students need to learn to choose representations with appropriate disciplinary affordances to enact a given IPDRA. In this paper we demonstrate the different disciplinary affordances of representations and how changing representation can lead to the possibility to enact different dimensions of disciplinary knowledge.