Graduate student teaching assistants (TAs) are often responsible for assessing student work, such as laboratory reports, and it is important that the same student effort be assessed similarly across TAs. Prior exercises with TAs showed a wide range of scoring among a team of TAs assessing the same lab report. A three-hour Professional Development (PD) activity spread over three weeks was conducted with TAs in a general chemistry course to gain skill in the assessment of lab reports within the context of working as a group. In week 1, TAs individually assessed an identical, redacted lab report. In week 2, TAs discussed their scoring of the first lab report, and then assessed and discussed selected portions of additional lab reports. During week 3, TAs assessed another redacted lab report. Results show a modest narrowing in TAs’ scoring from week 1 to week 3, which suggests this activity could be employed as part of a strategy to develop “community” standards among TAs.
