Friday, April 25, 2014

V: VAMs--Value Added Models Offer Little Value #AtoZChallenge


How should a teacher's effectiveness in the classroom be evaluated? 
That question is a real sticking point in education circles. I am evaluated at the building level and by my university supervisor for Idaho State University. How my teaching is evaluated differs greatly between these two entities. 

Value Added Models, a.k.a. Value Added Assessment, are the darling of the pseudo-education reform crowd and arguably the fuel for the many testing scandals of the past two years, including the one in Washington D.C. involving the tenure of Michelle Rhee. In Las Angeles teacher's rankings were published by the Las Angeles Times and resulted in one teacher committing suicide. 

A VAM purports to be an objective measurement of student progress--based on standardized test scores--in a given year. Thus, a VAM, theoretically, measures how well a student performs in a year, and this data is then used to evaluate the teacher. RAND.org has quite the website rationalizing the use of VAMs. It goes to great pains to justify VAMs as valid based on their accounting for factors other than the teacher. However, they only list a couple of variables. 

Recently, the American Statistical Association issued a statement warning against the use of VAMs in teacher evaluation systems. Diane Ravitch has sounded the whistle on VAMs consistently on her blog. 

Among the ASA's findings: 
  • VAMs are generally based on standardized test scores, and do not directly measure potential teacher contributions toward other student outcomes. 
  • VAMs typically measure correlation, not causation: Effects – positive or negative – attributed to a teacher may actually be caused by other factors that are not captured in the model.
The report cautions proponents of VAMs about the complexity of the models and the need to use them w/ caution and only by statisticians with advanced expertise. 

Despite these warnings, politicians forge ahead with the VAM bandwagon. On May 4 Rethinking Value-Added Models in Education by Audrey Amrein-Beardsley will be published and will shine a light on the dark side of VAMs in teacher evaluations. I suspect the book will also challenge VAMs as being detrimental to authentic learning. 

It's time the public began questioning the value in VAMs. 

**Update: After writing and posting this entry, I learned that Tennessee's governor signed legislation prohibiting teacher evaluations based on VAMs. Diane Ravitch has the breaking news. 

Then I saw a post indicating Washington state has lost its NCLB wavier because it has not tied teacher evaluations to metrics, such as VAMs. This, of course, is Arne Duncan's doing. He continues to show his utter disdain for teachers. See this for more

1 comment:

  1. Very informative and passionate post. Hopefully more states will follow suit after Tennessee.
    Deb@ http://debioneille.blogspot.com

    ReplyDelete