TAMPA — Some Hillsborough County teachers make a big difference for their students. Others, not so much.
District officials say they have always struggled to tell the two groups apart. Which teachers hit home runs and boost student growth, and which ones strike out?
On Tuesday, the School Board plans to settle the question by hiring consultants from the University of Wisconsin.
The $3.4 million contract is part of Hillsborough County's seven-year, $202 million partnership with the Bill & Melinda Gates Foundation.
The university's task: use student tests to calculate each teacher's annual "value-added" contribution to the district.
It's a question of national significance, said Christopher Thorn, associate director of the university's Value-Added Research Center in Madison, which performs such calculations for New York City, Chicago and Milwaukee schools and several states.
"Hillsborough's project is enormously ambitious," he said. "What Hillsborough is doing is what every one of them wants to do."
Beginning in 2011, the district hopes to use the value-added data — along with principal and peer evaluations — to help decide which teachers deserve tenure, promotions or dismissal.
By 2013, such information also will determine teacher pay.
"We need formulas for every teacher of every subject," said David Steele, the district's project director.
What makes Hillsborough's effort unique is its scope.
Other school systems have focused on measuring teachers' contributions in widely tested subjects like math and reading.
Hillsborough, by contrast, has developed end-of-course exams in most subjects in order to participate in Florida's pilot merit-pay program. States as far-flung as the Dakotas are interested in following that example, Thorn said.
"What's the pretest for Welding II?" he asked. "Well, they have one in Hillsborough."
Critics warn against relying too much on standardized tests to judge teachers. And some Hillsborough teachers worry they'll be penalized for teaching low-income students or those with special needs.
But even students with severe handicaps can be tested for growth, Steele said, vowing to make sure such measures are fair.
Thorn said value-added measurements are designed to filter out student differences in income, family background and other disparities to determine how much teachers contribute.
"This is knowledge work," he said, describing the need to measure teachers in multiple ways. "There's no way anyone, including the Value-Added Center, says that a test measures everything we care about."
Tom Marshall can be reached at firstname.lastname@example.org or (813) 226-3400.