are defining dimensions of expertise. However, knowledge and strategies, as
previously discussed, do not function independently but in concert. As indis-
pensable as knowledge and strategies to unraveling the mystery of expertise is
the dimension of interest. Not only is interest tied to domain-specific knowl-
edge, but it is also linked to strategies. Because general strategies are proce-
dures willfully or intentionally invoked, interest would serve as a catalyst
for their implementation. Thus, knowledge, strategies, and interest operating
in association represent essential keys to unlocking expertise. Of course, this
does not mean that knowledge, strategies, and interest are the sole factors that
explain expertise development. Yet they remain indispensable dimensions
nonetheless.
Knowledge. Subject-matter knowledge refers to an individual’s breadth
and depth of knowledge about a given academic domain, such as biology,
history, or physics (Alexander, Schallert, & Hare, 1991). From the outset, my
284 ALEXANDER
FIG. 10.1. The components and stages of the Model of Domain Learning, as
modified from Alexander, P. A., Jetton, T. L., & Kulikowich, J. M. (1995). In-
terrelationship of knowledge, interest, and recall: Assessing a model of domain
learning.Journal of Educational Psychology, 87, p. 560.