Zero Sum Game
There are many serious flaws in the Louisiana Act 54 evaluation system, but the most serious one is that it is a zero sum game. Here is the Wikipedia definition of a zero sum game:
a zero-sum game is a mathematical representation of a situation in which a participant's gain (or loss) of utility is exactly balanced by the losses (or gains) of the utility of the other participant(s). If the total gains of the participants are added up, and the total losses are subtracted, they will sum to zero. Thus cutting a cake, where taking a larger piece reduces the amount of cake available for others, is a zero-sum game if all participants value each unit of cake equally (see marginal utility).
The way the VAM portion of the teacher evaluation system was designed, there will always be 10% of teachers each year rated as ineffective. This will happen even though student performance may improve from one year to the next. The teaching force will never be seen as improving even if student scores go up statewide, because this zero sum system always dictates that
a zero-sum game is a mathematical representation of a situation in which a participant's gain (or loss) of utility is exactly balanced by the losses (or gains) of the utility of the other participant(s). If the total gains of the participants are added up, and the total losses are subtracted, they will sum to zero. Thus cutting a cake, where taking a larger piece reduces the amount of cake available for others, is a zero-sum game if all participants value each unit of cake equally (see marginal utility).
The way the VAM portion of the teacher evaluation system was designed, there will always be 10% of teachers each year rated as ineffective. This will happen even though student performance may improve from one year to the next. The teaching force will never be seen as improving even if student scores go up statewide, because this zero sum system always dictates that