Not in Sri Lanka but in New York City, USA.

(නෑ, නෑ, ඇමෙරිකාවේ, ඇමෙරිකාවේ)
Bonuses are only for teachers at schools with high concentrations of children from poor families. The unions have agreed with the condition that the incentives are to be given to a school and distributed evenly to all the teachers.
Here is the report:

http://www.nytimes.com/2007/10/18/education/18schools.html?th&emc=th

The Bloomberg administration and the New York City teachers’ union announced an agreement yesterday on a plan that would give teachers bonuses based largely on the overall test scores of students at schools that have high concentrations of poor children.

The plan, negotiated for months, is a major breakthrough for Mayor Michael R. Bloomberg, who for years has advocated extra pay to reward high-performing teachers.

In a bow to the union, the bonus money would go to schools for overall performance, and then would be distributed to teachers. The agreement also gave the union something it had long sought: city backing for senior teachers to retire with full pension benefits, five years earlier than they can now.

In addition, the city agreed to pay $160 million to settle a longstanding dispute over the city’s contribution to benefits for 40,000 retirees and teachers.

Mr. Bloomberg and Schools Chancellor Joel I. Klein announced the deal at City Hall with Randi Weingarten , president of the United Federation of Teachers. Calling it a “historic and unique agreement,” Mr. Bloomberg said, “This agreement puts New York City at the forefront nationally in finding ways to reward such high-needs schools for performance.”

Merit pay programs, which base compensation for teachers on their classroom performance rather than their seniority and academic degrees, have traditionally been opposed by teachers’ unions. But those programs, as well as other incentive pay plans, have been gaining ground across the country in recent years, and the movement is likely to get a major boost with this agreement in the nation’s largest school system.

“I think that this is a major breakthrough,” said Charles Brecher, research director at the Citizens Budget Commission. “This is a step over the line and a movement towards the principle that says we reward merit and not just seniority.”

New York City’s plan, which is contingent on the State Legislature’s expected acceptance of the pension agreement, is a twist on the traditional concept of merit pay. Pots of money would not be distributed teacher-by-teacher but are to be given to schools that have schoolwide gains in student test scores. It will be up to “compensation committees” at each school, made up of two teachers, the principal and a principal’s appointee, to distribute the money. They could choose to distribute it evenly among union members or single out exceptional teachers. They cannot distribute the money by seniority.

This school year, about 200 of the city’s high-needs schools — identified by factors like poverty — would be eligible for about $20 million in bonuses. They would initially be paid for with private money. Next year the plan is likely to expand to 400 schools and to be financed by the city.

The plan would not only give Mr. Bloomberg a policy change he has long sought, but also allow Ms. Weingarten, a potential candidate to lead the national American Federation of Teachers, to cast herself as a reform-minded union leader.

Both the Bush administration and Representative George Miller, the California Democrat who chairs the House Education Committee, have tried to promote the concept of pay for performance. But leaders of the two national teachers’ unions came out in opposition to draft legislation to renew the No Child Left Behind law because it contained a proposal to count student test scores in granting incentive pay.

Indeed, the issue is so sensitive that Ms. Weingarten took great pains yesterday to insist that she did not consider New York City’s new effort to be merit pay. “I think this is a concept that promotes collaboration on a school level,” Ms. Weingarten said. In fact, Ms. Weingarten said, “This shuts the door on the individual merit pay plans that I abhor.”

She said it had several “checks and balances” that distinguished it from plans she has opposed. Union chapters at each eligible school are to vote on whether they want to join the program. Schools are to be judged by their overall performance, not teacher by teacher.

If the schools meet certain performance goals, based largely and perhaps exclusively on test scores, they are to receive an amount that totals $3,000 per teacher.

If compensation committees cannot agree on how to distribute the money, they will forfeit it.

The mayor said he was pleased with the plan.

“In the private sector, cash incentives are proven motivators for producing results,” he said. “The most successful employees work harder, and everyone else tries to figure out how they can improve as well.”

Because the bonuses will be available only to teachers at needy schools, Mr. Bloomberg said he hoped they would “provide our best teachers with an incentive to work in high-needs schools.”