  As part of a larger study to understand instructors' considerations regarding
the learning and teaching of problem solving in an introductory physics course,
we investigated beliefs of first-year graduate teaching assistants (TAs)
regarding the use of example solutions in introductory physics. In particular,
we examine how the goal of promoting expert-like problem solving is manifested
in the considerations of graduate TAs choices of example solutions. Twenty-four
first-year graduate TAs were asked to discuss their goals for presenting
example solutions to students. They were also provided with different example
solutions and asked to discuss their preferences for prominent solution
features. TAs' awareness, preferences and actual practices related to solution
features were examined in light of recommendations from the literature for the
modeling of expert-like problem solving approaches. The study concludes that
the goal of helping students develop an expert-like problem solving approach
underlies many TAs' considerations for the use of example solutions. TAs,
however, do not notice and do not use many features described in the research
literature as supportive of this goal. A possible explanation for this gap
between their belief and practices is that these features conflict with another
powerful set of values concerned with keeping students engaged, setting
adequate standards, as well as pragmatic considerations such as time
requirements and the assignment of grades.
