knowledge, whereas the term understanding signifies a more
complex, multidimensional integration of information into a
learner’s own conceptual framework. To elaborate on their
definition of understanding, Wiggins and McTighe define six
facets of understanding and its complexity as compared with
knowledge, as shown in Table 1. To demonstrate understanding
in this framework, students must not only possess
rudimentary knowledge, but must also be able to explain,
interpret, and apply that knowledge, as well as have
perspective on the information, possess self-knowledge of
their own understanding, and empathize with the understandings
held by others.
Striving for student understanding as a result of instruction,
above and beyond memorizing or knowing, requires
that instructors take into account students’ prior knowledge
and support students in integrating new knowledge with
their existing ideas. An explicit confrontation between
preknowledge and new knowledge is the critical element
in teaching toward understanding put forward by Posner
and colleagues’ theory of conceptual change (Posner et al., 1982).
Although conceptual change theory has been defined by
science education researchers in a variety of terms, we define
it here as a learning process in which an existing conception (idea
or belief about how the world works) held by a student is shifted
and restructured, often away from an alternative or misconception
and toward the dominant conception held by experts in a field (Chi
and Roscoe, 2002; DiSessa, 2002; Posner et al., 1982). Learning
that accompanies conceptual change stands in contrast to
learning that is associated with the accrual of new ideas put
forward by others. Such accumulative learning is generally
not well integrated into students’ frameworks for understanding
and is thus not embraced by students in explaining
the natural world on a daily basis (Wandersee et al., 1994).
Teaching toward conceptual change, however, requires that
students consider new information in the context of their
prior knowledge and their own worldviews, and often a
confrontation between these existing and new ideas must
occur and be resolved for understanding to be achieved.
Thus, in teaching toward understanding of major concepts
in biology and achieving conceptual change for students, it is
first necessary to understand students’ prior knowledge,
examine it, identify confusions, and then provide opportunities
for old and new ideas to collide. In teaching toward
conceptual change, it is counterproductive to simply cover
more material and present an extensive list of new ideas
without engaging students in their own metacognitive
analysis. As advocated by many science education reform
documents, inquiry-based science teaching may be seen as
one strategy for teaching toward conceptual change, in that
inquiry engages students in the exact same questioning of
one’s preconceptions and challenging of one’s own knowledge
that is characteristic of both conceptual change and
scientific habits of mind. In this sense, working toward
conceptual change is fundamentally what scientists do in
laboratories every day, yet it is not generally the norm of
what students are doing in classrooms. If instructors are to
be successful in changing the way students think about how
living things work, in the same way biologists continue to
revolutionize our ideas about the same subject, then students
and instructors together must access prior knowledge and
uncover misunderstandings and incomplete understandings.
Perhaps paradoxically, students’ ‘‘wrong answers’’ may be
our best tool in crafting learning experiences that will move
them toward the ‘‘right’’ answers, at least ‘‘right’’ in the sense
that they are better aligned with current scientific evidence.