The Chicago Teachers Union has provoked a bitter battle with principals by asking its members to provide ratings of their bosses for an online scorecard.
The union announced last month that it would send questionnaires to 33,000 teachers and classroom assistants to elicit their views on principals'
professional strengths and weaknesses. The results of the anonymous poll will be posted on a website later this month.
President of the union, Deborah Lynch, justified the action by saying:
"Accountability is a two-way thing."
Principals, she added, get their say about teachers on traditional performance-evaluation forms.
But principals' representatives dismissed her argument: "If accountability is good for principals, it's good for teachers too," said Clarice Berry, head of the Chicago Principals and Administrators Association.
Ms Berry said teachers' representatives had halted the parental evaluation of teachers that is part of the Milwaukee scheme on which the CTU models its scorecard.
"We're just curious as to why CTU is only importing part of the process," said Ms Berry.
In a continuation of the sparring, Ms Lynch said last week that lack of leadership was a key factor in staff attrition. She noted that teachers who wanted to move to a new school could consult the website to find out what they would be letting themselves in for.
Ms Berry's assistant, Everett Edwards, said the teachers' poll was a "renegade action" liable to be hi-jacked by "disgruntled folks with axes to grind" and encourage disaffected staff to return multiple copies of their critical responses.
Ms Lynch said officials from the University of Illinois would be used to moderate the returns and ensure "fair representation".
But a slip of the tongue may have betrayed the politics underlying the dispute.
"There's always tension between folks who represent subordinates and their superiors." said Mr Edwards before he corrected himselfI "supervisors, I should say".