Here are the key findings in Texas against the use of VAM for evaluating teachers:
- The VAM system which was originally designed to measure farm efficiency is not comparable to teaching effectiveness.
- The American Statistical Association found that the impact of teacher quality on student scores was 14% at most. All the other factors such as socioeconomic deficiencies make the teacher portion almost insignificant in determining VAM.
- Some administrators were found to be basing the teacher observation portion of the teacher evaluation on the teacher's VAM score which totally invalidated the observation portion.
- High stakes tests which are used as the basis for VAM were never designed for teacher evaluation.
- The stability of VAM scores was found to be so erratic that it could not be relied upon to reliably evaluate teachers.
The major proponent of continuing to use VAM in Louisiana is the Louisiana Association of Business and Industry (LABI). LABI has appointed itself as the expert on teacher evaluation, and uses its power over the legislature to keep the VAM evaluation going. LABI likes the VAM system because it results in stack ranking of teachers, with the bottom portion of the ranking being subject to dismissal or humiliation leading to resignations. It is interesting to note that when stack ranking was used in private business it was quickly abandoned because it resulted in productivity losses. Why then is LABI insisting it be used on teachers?
LABI also does not take into account that only about 35% of teachers are subject to VAM because the other 65% do not teach students taking state tested subjects. This fact puts VAM rated teachers at a disadvantage in receiving merit pay or facing dismissal. Why would Louisiana want to continue a system of evaluation that punishes only certain teachers teaching core subjects? This is serious discrimination!