[LDale]

Teachers/administrators/schools do not have their funding tied to the improvement of their high-performing students.

This is a natural by-product of the Texas model of educational reform (NCLB/Race to the Top/etc.): teachers cannot be trusted to teach and assess their students where those students might be (with regards to content mastery) so we implement standardized tests which focus attention on the lowest performing students (often overwhelmingly teaching them test-taking skills irrelevant to real life) and thereby reducing the time allotted to core curriculum for everyone. It's a system that only improves academics on a superficial level (raising scores without raising academic mastery) and diverts billions of dollars out of already constrained school budgets to private testing/content material providers (NCLB requires tests and other measures without providing resources to implement them - hence resources must be stripped from other programs or services at the schools).

[yummyfajitas]

Standardized testing is orthogonal to focusing on the lowest performing students.

You could use standardized tests and focus on top students just as easily - we just focus on the underperformers because that's what our political culture demands.