Tuesday, June 3, 2014

What the Star Rating System Tells Us, Part 2

The Star Rating System provides a limited portrayal of the quality of a school, mostly because it relies only on growth and achievement in standardized test scores (elementary and junior high), or on those measures and college-ready courses and test scores (high schools). However, given its limitations, the system does provide comparative achievement and growth information about schools across the state.

As indicated in part 1 of this post, elementary and junior high Star Ratings will likely see some revision of growth/achievement weighting by the Star Rating Committee, but will retain the same basic structure.

However, the high school ratings are problematic, in that they tell us little about the achievement outcomes of schools across the state, and instead rely too heavily on growth. Chester Finn, Jr. made an argument for using achievement as the primary measure in rating high schools.

So, if we could adjust the weighting for high schools, could we more accurately reflect outcomes and preparation for post-secondary? Yes, if we used a formula something like this:
  • Achievement – 45%
  • Growth – 20%
  • Graduation Rate – 10%
  • Advanced Opportunities – 25%
In this proposal, fully 70% of the points in the rating system would be earned through college-readiness achievement and course-taking patterns. The effect? High schools with the most students taking Dual Credit or Advanced Placement coursework and showing evidence of college readiness on the SAT or the SBAC would have the highest ratings. For example, using growth points, high school graduation, and advanced opportunities from the old system and reweighting them with 2013 SAT performance, the highest ranked schools would be:

Note that every high school received the maximum possible points for high school graduation and for advanced opportunities. Idaho's high school graduation rate is among the best in the nation, so that makes some sense. But the bar for advanced opportunities is set at a very low level. In fact, only 25% of juniors in the high school had to take an advanced opportunity course (AP, Dual Credit, Tech-Prep, International Baccalaureate), as long as 90% of the students enrolled received a grade of "C" or better, for the high school to receive the maximum number of points.

Comparing to the chart we used in Part 1, we see that the proposed weighting system better reflects achievement outcomes in Idaho high schools.

So what happens to high schools that rated 5 stars on the 2013 Star System, but had lower preparation indicators on the SAT?

Even though the Star system is an imperfect measure of school quality, this proposal provides for consumers a better indicator of college and career readiness among Idaho high schools.