The lame duck is acting like a bantam rooster.

Mayor Bloomberg’s fuss-and-feathers over use of student performance data in teacher tenure decisions is a short-lived diversion, like his presidential run during a previous lame duck period. Legal authority for his position is questionable and of little practical consequence. At best, under current law, he has one year to try to work his will but no principal’s tenure decision will change based on this new edict. Weakened by his slim re-election margin, Bloomberg’s tantrum is an understandable political strategy to appear politically strong. But our education plight is too important to be distracted by this sideshow.

The mayor invokes that portion of New York State Education Law § 3012-b as added by Chapter 57 of the Laws of 2007 which permits principals to make teacher tenure determinations based on “an evaluation of the extent to which the teacher successfully utilized analysis of available student performance data” and the more elastic “assessment of the teacher’s performance by the teacher’s building administrator.” The law was clarified by Chapter 57 of the Laws of 2008 to prohibit use of student test scores to grant or deny tenure. But even if the earlier version is found to permit use of test data for current tenure evaluations, State Education Commissioner’s Regulation § 100.2(o)(2)(iii) appears to prevent this use unless included in probationary teachers’ “professional performance review plan,” a formal document that must be developed “in collaboration with teachers … selected by the [Chancellor] with the advice of their respective peers.” Collective bargaining issues also exist as a change in the terms and conditions of employment. As a result, it is doubtful that the mayor’s unilateral analysis has much legal weight.

Rather than hastening their exit, the mayor has created a legal loophole for ineffective teachers to remain in classrooms.  What the mayor has actually done is to hand every failing teacher, already on the chopping block based on principals’ prior determinations, a ready argument that his or her tenure was denied on illegal grounds. Principals already know who they want to fire and have developed their own grounds to deny tenure. At best, test scores will provide an additional, controversial excuse. And those who principals want to keep will surely not be fired on the basis of test scores alone. This grandstanding —Bloomberg didn’t even let the chancellor announce the move, so impatient was he to garner public credit — will thus have the reverse effect of its purported intent. The mayor has made martyrs of the system’s dross.

Test scores from the first few years of a teacher’s career are relatively meaningless anyway. Even if some test scores, interpreted correctly, turn out to be valid measures of long term teacher quality, our current three year tenure clock is too short to make that determination. How can a fair evaluation be made from test scores during the first year on the job? Other data such as classroom management, content knowledge, and the ability to improve will be more determinative of retention. So the second year becomes the benchmark to compare to the third year, if the testing calendar allows. But this permits insufficient data for a studied tenure determination. Other measures, especially classroom observations which I strongly encouraged in my last column, are more likely to provide usable information. The mayor seemed to admit as much in his recent Washington speech but continues to give principals too little time to practice what he preaches.

In sum, the mayor has picked the wrong battle. Nonetheless, if he really wants to use student test data to evaluate teachers for tenure, his first step should first be in Albany, convincing legislators to adopt a probationary period of at least five years, effectively extending the period for at will termination and giving slow starters a chance to prove their mettle. Five years’ experience would allow for meaningful, long-term evaluation of teachers’ growth and the justifiable reward of tenure that would follow.