Wednesday, February 4, 2015

Three Reasons Why VAM Fails in Louisiana

The Value Added Model (VAM) for teacher evaluation was adopted by the legislature as a way of improving or removing ineffective teachers and rewarding good teachers. It does a very poor job on both objectives. But in addition, VAM has some very destructive effects on the teaching profession and on student instruction.  Here are three reasons why VAM is counterproductive.

Number one: VAM drives away some of the best potential teachers from the basic skills subjects of Math and ELA. Only one-third of teachers are rated by VAM because the majority of teachers teach non-state tested subjects. VAM ratings focus primarily on Math and English language arts teachers. The rest of the teachers are rated by their effectiveness in reaching student learning targets. But since VAM scores are so erratic, many excellent teachers do not want to subject themselves to the possible humiliation of an "ineffective" rating if they are qualified to teach some other subject.  Present law states that any teacher getting an ineffective rating immediately loses tenure and must undergo intensive remediation. Also, statistics based on the first year of VAM and several years of simulations demonstrate that VAM rated teachers are only one-third as likely as non-VAM rated teachers to get a “highly effective” rating on the quantitative part of their evaluation. (I will explain why under reason number two).  Since the new state mandated merit pay system rewards mostly teachers rated as highly effective, VAM teachers are much less likely to get merit pay.  For these reasons, many good Math and English teachers are opting out of teaching those subjects.

Number two: The VAM quota system does not allow for a general improvement of teacher evaluations as student scores go up from year to year. The way VAM is supposed to work is this: Complex formulas calculate each teacher's expected composite class scores on the state tests each year based on student's past records and socio-economic factors. The VAM than rates teachers on how well their students perform compared to their expected test scores. The problem is that no matter how well students statewide do from year to year, the LDOE limits the percentage of teachers that can receive each classification of ratings. The LDOE ranks all 16,000 VAM teachers from highest to lowest VAM scores and rates them based on mandatory percentages for each level of the ranking system. For example, teachers ranking in the top 20% of the rankings get "highly effective" and teachers ranking in the bottom 10% get "ineffective".  How the teacher ranks compared to other teachers determines the teacher’s final VAM rating. So if students statewide progress greatly from one year to the next, you still have the same 10% of teachers who get a failing score and only 20% of teachers getting an excellent score. The system guarantees that the same percentage of teachers will fail each year no matter how students progress or regress on state tests.

Number three: The VAM system guarantees that in the basic skills subjects, experienced teachers will be systematically replaced by less experienced and probably lesser trained teachers. Since the VAM system rates 10% of teachers "ineffective" every year no matter how well students do, the system will cause much more turnover of teachers in the basic skills subjects. New teachers with less experience and training usually replace these teachers. So the actual quality of instruction in the basic skills will most probably go down instead of up.


Present law requires that 50% of a teacher's evaluation is based on her/his VAM score. It has been suggested that the percentage of a teacher’s evaluation based on VAM should be reduced as a way of mitigating its effect on the teacher's overall rating. But reducing the percentage based on VAM just means that VAM will do less damage to the teaching profession and to the instruction of children. Since VAM does nothing positive to improve teaching, it should not be used for any percentage of the evaluation system.

1 comment:

Anonymous said...

Really well-thought, Mike. And succinctly stated. There will be push back on this as business is submitting their own version of how evaluation of teachers should occur. I sent you that plan in an email. I hope to speak to you about it before the Subcommission on Accountability. Debbie Meaux