John Merrow on the Value Added Model

I think pretty highly of John Merrow; the podcasts that he puts out are always well worth listening to, and the segments that he does for PBS are quality education journalism. In the June 13th edition of Education Week he has an interesting commentary on using growth models to measure the progress that schools and the students in them make; a part that resonated with me was this:

...to have a valid growth model, schools need what families have: a common yardstick. But schools also need a generally agreed-upon (and nourishing) curriculum. So if we want to develop a valid “growth model,” we first need to debate what belongs in the curriculum and figure out what sort of performance measures make sense.

It’s perhaps the most important question since the rise of NCLB: should the testing drive the curriculum, or should the curriculum drive the testing? The limitations and strengths are nearly identical with either approach:

*If we base our tests off of the curriculum, we can accurately measure how well they learned what was taught. This allows for discussions of teacher effectiveness, because they’re the ones who taught the material. The weakness in this approach is that the curriculum might not cover everything that is believed essential for that grade level, which creates gaps in learning that can have a terrible cumulative effect if allowed to grow over time.

*If we base our curriculum off of our tests, we can help to ensure that kids are being shown what has been deemed important, because what’s tested is what’s taught. If we believe that’s what tested is important, this is a good thing. This allows for discussions of school effectiveness, because the yardstick is the same for everyone statewide and we can see which buildings “get it” and which don’t. The weakness in this approach is the overwhelming number of learning requirements, more than can realistically be taught in most grades, which perhaps leads to a narrower curriculum.

This is why I’d like to see more school around the state using the MAP assessment from NWEA, and school-wide scores being made more readily available for study. One of the biggest weaknesses I see in the WASL is that a 1, 2, 3, 4 scale doesn’t tell you nearly enough about where you’re at as a school. The MAP breaks the scores out into the basic areas of reading and math and can be used to measure their growth from the beginning of the year to the end, which is also much more useful than the WASL, which comes back 5 months later.

Growth models: I like ‘em!