Getting Value-Added Right

Moving to the growth or “value-added” model of assessment, seems to be the favorite education reform of the incoming Obama administration, notes the Washington Post’s Jay Mathews, who seems to favor the idea.  ”The growth model appeals to parents because it focuses on each child,” he writes.  “It gives researchers a clearer picture of what affects student achievement and what does not…The next step would be to use the same data to see which teachers add the most value to their students each year,” he writes before noting the objections to value-added among teachers and unions.

Go ahead. Blame the teacher unions. They make no apology for their opposition to this approach. But they have good arguments. Congress will have to revise the No Child Left Behind law to install the growth model, and most support for the idea there extends only to rating schools, not teachers. Assessing instructors by how much their students improve seems reasonable to people like me who have never taken a psychometrics course, but nobody has sufficiently tested the statistical devices for doing that, and they might prove to be expensive.

I’ve never taken a psychometrics course either, but at the elementary school level, it’s the rare teacher who would be comfortable having his or her fortunes tied to value-added measures for the simple and obvious reason that there are too many variables impacting student achievement that an individual teacher cannot control, or even influence.  Try this analogy: 

Let’s say you’re a waiter working the lunch shift at a restaurant with lots of repeat business.  The owner  wants to make sure that sales per diner and customer satisfaction are going up.  That’s perfectly reasonable.  But instead of looking at the average sales and customer satisfaction, the owner wants to hold you accountable for every single diner you serve.  They all need to go up.  If even a single diner leaves unhappy and spends less, you’ve failed.  Your job is to make sure that every customer is happier today than they were with yesterday’s lunch and spends more, even if they ate at a different restaurant.  Since yesterday, the customer may have had a tough day at work, argued with his spouse, or got in an accident in the cab on the way over.  He may not even be very hungry today.  It doesn’t matter.  If you’re really good at what you do, you should be able to overcome every obstacle since studies show the most important variable in customer satisfaction is the waiter.  You have no control over the menu, the meal, the seating, the decor, or the customer’s interactions with the hostess, the bartender, the busboy and every other staff member.  By the way, if you work at Denny’s your customers are expected to be just as happy as they are at Le Cirque. 

After the appetizers are cleared – not even at the end of the meal – the customer satisfaction survey is dropped on the table.  Meawhile, at a different waiter’s table, another customer is having a terrible time.  The waiter is rude, the food is cold, and the busboy spilled water on him.  He’s filling out a survey too.  Half of his evaluation will be charged to you, since you served him lunch yesterday. 

Fair?

None of this should be taken as an attack on the idea of accountability, or even value-added.  I’m a firm believer that as teachers, we need to hold ourselves to very high standards and be accountable to the taxpayers who pay our salaries.  Accountability matters a great deal.  But poorly designed and executed accountability measures will set back the cause of accountability, perhaps irrevocably.  We’ve got to get this right, not engage in another round of ready-fire-aim.

4 Responses to “Getting Value-Added Right”


  1. 1 Dan Willingham

    Why is it not an attack on value-added more generally? I think it should be.
    You didn’t mention the statistical problems with value-added measures, which are formidable. As they stand, the measures are NOT reliable.
    The idea of value-added assessments has enough promise that it seems like the measurement folks should keep on working on it, but it is clearly not ready for implementation.

  2. 2 Robert Pondiscio

    Why not? Because I see a lot of promise in the idea in evaluating schools as a whole (at least when tracking students in the same school over time). Where it leaves the rails for me is in using it to evaluate individual teachers.

    Readers note: Dr. Willingham has a terrific post on value-added over at Britannica Blog, which includes the statistical issues he alludes to. Here’s a link:
    http://www.britannica.com/blogs/2008/11/how-not-to-evaluate-teachers/

  3. 3 Rachel

    “Value added” is a concept that, like “continuous improvement” has considerable appeal. But many of the most vocal supporters of accountability seem to have difficultly realizing that concepts don’t translate easily into employee evaluation systems. Very few private businesses evaluate their employees in ways that are as simplistic as many of the proposals for evaluating and compensating teachers.

  4. 4 Nancy Flanagan

    The Mathews column evidently rang a lot of chimes yesterday. It was my blog topic, too, in a post called “The Audacity of Pumpkin Pie:”

    http://tinyurl.com/5qs9kj

    Rachel’s right–the concept of “adding value” is attractive–but using VAM to identify effective teaching (or, God help us, fire the lowest quintile) is, as Dan points out, the elevation of cool statistics over substance. I have heard any number of data experts, including Dan Koretz and Dan Goldhaber (what is it about the Dans?) debunk the idea that VAM is the way to go in identifying effective teaching.

    As a former waitress-your-way-through-college type, I really appreciated your analogy. But ask any caring teacher to tell you a personal story about a smart kid who had a bad year when his parents divorced, and you won’t need an analogy. We do need to delineate, identify and recognize efficacious teaching. But we need a full toolbox to do it.

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