What Students Know
Constructivism and Preconceptions
• An epistemology which states that
students are not “blank slates,” but
actively construct their knowledge from
their experiences of the world.
• Problems should have
personal meaning for
• Thinking arises when a
learner confronts a
• The mind applies prior
knowledge in the
struggle for a solution
• Knowledge arises from an
interaction between individuals
and their environment.
• Knowledge is not “out there,”
but created and recreated
internally from prior and new
• Development interacts with
• Knowledge is socially
• Imitation and modeling are
critical in the learning
• The Zone of Proximal
learners to increased
• “The most important
single factor influencing
learning is what the
learner already knows;
ascertain this, and
teach him accordingly.”
• Knowledge is communicated, but not
• A learner’s prior knowledge determines how
the new ideas are interpreted.
• Knowledge is constructed as the learner
creates links between new and prior
• Prior mental models create a filter through
which new knowledge is interpreted.
Or Knowledge in Pieces?
• The concept that students hold strong
mental constructs of ways in which the
world works. These constructs are highly
resistant to change.
• Example: Many students and adults
believe that summer is warmer than
winter because the earth is closer to the
sun, in spite of teaching to the contrary.
Knowledge in Pieces
• The concept that a learner’s concepts
are composed of small bits of
knowledge, which are assembled on the
spot when asked for an answer.
• Example: A student who is asked to
predict the outcome of a physics
demonstration and sees the prediction
did not happen immediately comes up
with a new, different explanation.
“What I know isn’t so!”
• Preconceptions are concepts that
students hold prior to instruction, which
may or may not reflect current scientific
• All people have “misconceptions,”
because no one can know all there is to
know about science — not even
Sources of Misconceptions
• Daily experience: “The moon grows and
shrinks.” “The earth is flat.”
• Cultural ideas: “The stork brings babies.” “All
wild mushrooms are poison.”
• Textbook diagrams: “Atoms, molecules, and
cells are about the same size.”
• Personal theories: “Worms must be baby
• Uncovering misconceptions allows
teachers to apply a constructivist
• Once student misconceptions are
known, teachers may be able to create
lessons that test or confront the
Uncovering Student Ideas
• Interviews: Used frequently in research.
• Written surveys or tests: Limited by
student writing abilities, but often used in
conjunction with interviews.
• Card sorts: Useful for examining
personal categories of knowledge.
• KWL charts: For assessing a whole
• The Conceptual Change Model:
• Student ideas must be made explicit.
• Students are presented with discrepant
events or ideas that challenge
• Students struggle to create a new
model, which must be fruitful for the
student in order to be accepted.
• Students will only make their ideas
explicit if they feel safe in doing so.
• Confronting misconceptions carries the
danger of making students feel “stupid”
when they find out that what they thought
was so isn’t so.
• Students who feel stupid may shut down
and even refuse to participate.
Safe Learning Zone
• Teachers can create a “safe learning
• modeling conceptual change. “Wow,
looks like my idea didn’t fit the data. I
• being willing to say, “I don’t know. Let’s