  Teaching assistants (TAs) are often responsible for grading student
solutions. Since grading communicates instructors' expectations, TAs' grading
decisions play a crucial role in forming students' approaches to problem
solving (PS) in physics. We investigated the change in grading practices and
considerations of 18 first-year graduate students participating in a TA
professional development (PD) course. The TAs were asked to state their beliefs
about the purpose of grading, to grade a set of specially designed student
solutions, and to explain their grading decisions. We found that after one
semester of teaching experience and participation in PD, TAs did not
significantly change their goals for grading (i.e., a learning opportunity for
both the student and the instructor) or their grading practice. In addition,
TAs' grading practice frequently did not align with their goals. However, some
TAs' perceptions of the level of explication required in a student solution did
change. Our findings suggest that in order for PD to help TAs better coordinate
their goals with appropriate grading practices, PD should focus on TAs'
perception of sufficient reasoning in student solutions.
