Standardized test scores are worst way to evaluate teachers
COMMENTARY BY ISABEL NUNEZ September 12, 2012 7:26PM
As a university professor and educational researcher, I sometimes feel like I’m in that old ’50s horror movie, “The Blob.” Remember that one, where an invader from outer space grows with everything it eats, until it is a giant monster that threatens the entire town? Testing has done the same to education, harming students and schools — and is now poised to bring down the whole enterprise by taking over teacher and principal evaluation.
I am part of a group called CReATE, or Chicagoland Researchers and Advocates for Transformative Education, which is trying to unite the voices of academics in opposition to these changes and to the corporate takeover of public education. We are trying to spread the message that what is happening in our schools today is not supported by the research.
Standardized testing has become monstrous, which brings us to the proposed changes to teacher evaluation: the latest and worst use of testing so far. The Chicago Public Schools are planning to implement evaluations based in part on student test scores this school year. Terror at this prospect prompted CReATE to gather 88 signers on an open letter criticizing the plan, which we hand-delivered to the mayor, schools CEO and the Board of Education.
This new evaluation plan alone makes a strike no “choice” at all.
First, testing is not the way we should measure student growth. Large-scale educational testing was born in the early 1900s at a particular time in history: the industrial revolution. Some might argue that this was appropriate when preparing for the early 20th century work force, but in today’s globalized, information-based economy, “student growth” must be more meaningfully defined and assessed.
Next, if we are going to make the mistake of reducing student growth to a line graph, we must at the very least abide by the principles of measurement. The discipline of testing, called psychometrics, is governed by rules, and the new system of evaluation breaks some of the most fundamental rules.
The first important consideration of testing is purpose. The process of test construction is so specialized that an instrument designed for one purpose cannot be used for another. Even if we use the best tests possible, it is a core truth of psychometrics that no test is completely reliable: Error is part of every score.
For this reason, test developers, academic bodies and professional associations alike warn against attaching severe consequences to performance on any test.
It gets even worse from there. The way that CPS plans to use test scores in teacher evaluation, referred to as value-added, is so incredibly flawed that almost no one with a knowledge base in this area thinks it’s a good idea.
The National Research Council wrote a letter to the Obama administration warning against including value-added in Race to the Top federal grant program because of a lack of research support. The Educational Testing Service, an organization that stands to benefit tremendously from any expansion of testing, issued a report concluding that value-added is improper test use.
These are the people who know the statistics, and none of them thinks the models work. There is a list of obstacles:
One: A correlation does not mean a causality. Researchers have found fifth-grade teacher “effects” on fourth-grade scores using these models. Ridiculous, right?
That’s because the models don’t work. For one thing, there must be random assignment of students for this kind of comparison among teachers to work — and no administration that cared about students would ever do that. There are deep statistical problems, and no way to reduce the amount of error to an acceptable level. The biggest problem of all, though, is that this is a ranking. So half of all teachers will always be below the 50th percentile. That’s math.
This is setting teachers up for failure. This will ensure regular turnover, keeping the teaching force young and inexperienced, afraid and compliant. This is only one of many ways that teaching is being turned from a vocation to a job — and a low-paid, temporary one at that.
The Fordham Foundation issued a report this year, on teachers in the age of digital instruction, which talked about how we need to harness the power of technology to give students across large areas access to “media-genic super-instructors.” It literally proposed having “star” teachers onscreen, with “monitors” in the classrooms.
It suggested that teachers unions should look more like entertainment-industry unions, with “stars” commanding market rates, and the rest guaranteed minimum wages and benefits. These conservative think tanks are where policy is being formulated nowadays. Isn’t the personnel office in CPS now called the “talent office”? Thank goodness the Chicago Teachers Union is standing up to this madness. Teachers, working people and concerned citizens around the country are watching you, like heroes on a movie screen, with hope.
Isabel Nunez is associate professor at the Center for Policy Studies and Social Justice at Concordia University Chicago.