A Bad Idea?

Performance related pay schemes work well in manufacturing where the workers performance can be assessed by simple criteria such as time taken to complete the process, number of units produced, and quality of units produced. The best performing workers produce the highest number of quality items in the least amount of time and deserve more pay for saving the time and money of their employers. This system assumes the same inputs, essentially the same processes, and the same required outputs. The high performing worker may alter the processes in some way but for all workers the inputs and outputs are constants. The process of teaching individuals involves a multitude of variables at each and every stage.
Students as Raw Materials
The supposed Jesuit maxim 'Give me a child until he is seven and I will give you the man.' proposes that working with an infant full time from birth to seven years can give some lasting predictable outcome but the reality is that most teachers only teach a particular student for two to four years out of their compulsory thirteen years of formal education (NSW Australia) and this only commences after the child is four and a bit years old. Every teacher from preschool to University relies to a certain degree on the prior learning of their students. Is it fair to evaluate a particular teacher's performance without taking into account the nature of the 'raw materials' they have been given? This nature is not only determined by the students previous educational experiences but by factors such as their family composition, moral and ethical upbringing, socio-economic background (not only of the students themselves but of the school community as a whole), and the list goes on. As far as most departments of education are concerned teachers are to teach to individual learning styles and provide diversity in programs to cater for individual students, some students are even to be provided with Personal Learning Programs. Obviously teachers are expected to deal with students as unique individuals, even in classes of 30, and not as the raw ingredients in some sort of educational sausage factory.
Schools: The Factory Floor
Free and compulsory education has always been a thorn in the side for western societies. It is most often seen as a necessary liability rather than an asset and is treated accordingly. Because of this attitude schools vary almost as much in physical and human resources as the individuals taught in them. It is true that quality teaching has and will occur in the simplest of environments and in surroundings such as these it is easier to separate the quality of pure teaching from the resources that are available and from the behaviour of students (unfortunately it seems that the poorer the scenario the more attentive and appreciative the students). Is it fair to evaluate the performance of a teacher who has regular access to such things as new and innovative teaching technologies and classroom help in the form of student support teachers and technical assistants, on similar criteria to one who doesn't have access to these facilities or services? How can these, often immense, factory floor variations be taken into account when determining teacher performance?
Students as Manufactured Items: When I Grow Up I'd Like To Be
It's no wonder that teaching as a manufacturing process just doesn't work when the raw materials are given a say in determining what the final product is going to be. Students are the main decision makers in the education process. They always have been and always will be. The old adage 'You can take a horse to water but you can't make it drink.' applies here. The highest performing teacher, by any criteria, can not make a student who doesn't want to learn, learn. How is the teacher's performance assessed in this instance? I suppose trained and highly qualified observers (high performing teachers in their own right) could determine that a teacher was performing at a high level despite the results of their students. Not very cost effective I would think. The other problem with most students (and their parents) is they have widely divergent and individualistic views as to what constitutes a good educational outcome and many of these outcomes are not currently examinable or statistically valid as far as educational systems are concerned.
Performance Pay In People Jobs: It Just Doesn't Work
Teacher pay by performance is just not viable. Governments need to realise that professional people who work with people, as teachers do, have too many variables in their occupation to evaluate their general performance to any realistic measure. It is easy to identify the ones who are simply not doing the job and deal with them but paying the rest on the level of their performance is too fraught with difficulties. Can anyone really image paying doctors, nurses, policemen or fire fighters on their performance?