If there were only a crystal ball that could tell if a new recruit was going to become an effective teacher, so many seemingly intractable problems would be solved. But until that crystal ball is invented, states and districts continue to look for ways to make better predictions. The latest strategy is performance-based assessments, licensure tests that aim to measure what new teachers are actually able to do. Ever so trendy, California is at the center of the craze with its "Teacher Performance Assessment (TPA)"--a prelicensing measure that requires teacher candidates to submit teaching artifacts that "prove" their ability to plan for, review, and respond to student needs.

Nineteen states, as part of the Teacher Performance Assessment Consortium, are ready to jump on the bandwagon, but does the TPA really separate wheat from chaff among prospective teachers? That question remains unanswered. There are plans by researchers to examine data from California's recently completed pilot to determine if the TPA is comparable to other teacher tests, as well as plans to explore if TPA scores are predictive of student achievement.

A handful of states have even committed themselves to the TPA through legislation, and several others have pledged to come on board if the pilot proves the assessment to be valid. But there appears to be little evidence (available publicly, at least) that the TPA is a useful screen. The two states that currently require the Praxis III performance-based assessment report pass rates of about 99 percent. Given that it takes significant resources to administer a performance-based assessment, a test that nearly every teacher passes is of questionable value.

Perhaps Edward Crowe of the Woodrow Wilson National Fellowship Foundation said it best: "If [the assessment] doesn't support accountability for individual teachers, if they're going to report 96 percent pass rates, and if weak programs in these states aren't forced out of business, then I would say we haven't gotten anything better from this."