The Why2-Atlas system teaches qualitative physics by having students
write paragraph-long explanations of simple mechanical phenomena.
The tutor
uses deep syntactic analysis and abductive theorem proving to convert
the
student’s essay to a proof. The proof formalizes not only what
was
said, but the likely beliefs behind what was said. This allows
the
tutor to uncover misconceptions as well as to detect missing correct
parts
of the explanation. If the tutor finds such a flaw in the essay,
it
conducts a dialogue intended to remedy the missing or misconceived
beliefs,
then asks the student to correct the essay. It often takes
several
iterations of essay correction and dialogue to get the student to
produce
an acceptable explanation. Pilot subjects have been run, and an
evaluation
is in progress. After explaining the research questions that the
system
addresses, the bulk of the paper describes the system’s architecture
and
operation.
For a PDF full article version, click
here (591KB).