A review of some contemporary studies based on an individual-differenc
e model of student learning is presented. The exploratory 'fitting' of
conceptual models of student learning to atypical individual-similari
ty data structures is discussed, and an experimental categorisation pr
ocedure for producing such structures is outlined. Insofar as the feat
ures of some established conceptual models of student learning do not
'fit' such atypical structures, either by virtue of their conceptual p
arsimony, or their underlying conceptual assumptions, the 'fitting' of
a locus model to such structures is explored. It is argued that, with
in the 'student experience of learning' framework, conceptual models o
f student learning need to incorporate such additional dimensions of v
ariation if such models are to be employed in individual-difference st
udies of student learning.