To answer the requisite question that most evaluation tools don’t distinguish between good and excellent instructors, we cite Weisberg et al. (2009) which finds that over 90% of instructors receive the top two ratings on a point scale for evaluation, with less than 1% receiving an unsatisfactory mark. When instructors were asked to rate themselves on a scale of 1 to 10, over 85% rated themselves an 8 or above. The same report offers suggestions such as a comprehensive evaluation plan, training administration in conducting evaluation, and rewarding good teaching.
One evaluation system that has found success is TAP. From the National Institute for Excellence in Teaching, Daley & Kim (2010) report on the TAP system that was able to produce a normal distribution of instructor evaluation ratings, differentiating good instructors from exceptional instructors. A key point for their success is the use of measurement across multiple (4) dimensions with multiple ratings for each dimension that are averaged out.
As an alternative to “grading” instructors on a fixed-point scale, instructors can be promoted to higher roles reflecting their cumulative capabilities as an instructor. An example of this is the Royal Academy of Engineering Career Framework for University Teaching (RAENG, 2018).