A lot of ideas that make sense on paper (especially regarding teacher pay and teacher training) rest on being able to accurately (and fairly) evaluate teachers. This leads to two major questions: who should evaluate teachers and how should they do it?
The how is a more complicated question than I care to address right now, but I've frequently thought about the who last couple years, particularly given the problems I noticed with evaluations while I was teaching. The issue also came up in my last class -- where it was essentially batted around by a lot of former teachers. Based on previous thoughts, current practice, and recent discussion, these seem to be the options:
-An Administrative Supervisor (e.g. Principal or Asst. Principal)
-A Non-Administrative Supervisor (e.g. Dept. Chair)
-An Outside Expert (like in Martinique)
-A Mentor or Coach
-Some combination of the above
If you're a teacher (especially if there's a lot riding on the evaluation), you want to be evaluated by somebody who:
1.) Is an expert
2.) Knows you/your teaching well
3.) You can trust to be fair and impartial
The problem is that none of the options (save possibly the last one) meet all three of these criteria.
Administrative supervisors might meet all or none of these criteria depending on the situation. For example: a former English teacher who becomes a principal would not likely be an expert in teaching physics (and vice-versa). Whether your principal knows you well or is trustworthy depends on the circumstances.
I don't think there are many non-administrative supervisors. How many department chairs really count as supervisors? I'm sure exceptions exist, but the question then becomes what responsibilities these people have other than evaluating and if any of these are conflicts of interest.
I'm also not sure that I've ever heard of teachers bearing responsibility for evaluating other teachers (other than faculty making tenure decisions). I think there's some merit to this idea, but the largest problem is that it could negatively affect teacher communities, or at least make them artificial (e.g. people only say good things about themselves).
The outside expert could be both knowledgeable and impartial, but how well will they actually know the teacher?
The mentor or coach may best know your abilities, can they really be an effective source of guidance if they're also in charge of evaluating somebody (e.g. why would somebody come to them with their problems?).
Do we pick what we think is the best of these options, come up with something else, or combine these? Why not have an evaluation committee made up of some people from all walks of life? Imagine a committee made up of some teachers, administrators, and experts who were in charge of evaluating a number of teachers. Would this work? Would this be too cumbersome? Would it be worth it?