Hi Susan:
Rubrics might work for establishing the scale from mastery to unacceptable. The problem is it takes time to customize well written rubrics for a variety of lab skill sets.
Lab is hands on. Repetition is an important factor in suucessfulness. Some portion of the grade could come from the degree of practice sessions (participation).
The most important key is that whatever method used, it is aligned with minimal level of successful skill demonstration.
Regards, Barry
