Good article Ruben. I agree that too often evaluation systems like this are used as a punitive measure rather than a tool to shine a spotlight on teachers needing more support and personal development.
The challenge I have is with comments like “ The data collected by an expert educator closely watching the teaching and learning in a classroom over an extended period of time should be considered just as reliable and valid as a number generated from a complex algorithm”. Education has been plagued for to long with well-meaning people trotting out ineffective methodologies that don’t increase learning. It is not that the expert should be considered just as reliable, it needs to be demonstrated that this is as reliable and then that the corrective training will lead to improvements in the field. For too long Education has held on to the fallacy that you can’t put objectivity into the field, as if it were somehow different from every other industry. It needs to behave far more like Medicine where patients came with different backgrounds, doctors have different preferences on treatments but in the end we look to objective end outcomes of patients to both evaluate the effectiveness of the doctor and the methodology.
Personally I feel that teacher evaluation should be viewed as a tool to help students. We know that teachers are the most critical influence on student learning (for more check out John Hattie’s book Visible Learning) and so if students aren’t performing this is a way to help teachers understand how they need to improve their practice to help the students.