This is the VOA Special English Education Report.

More than half the teachers in the Houston Independent School District, the largest in Texas, have earned merit pay awards this year. Marjorie Hunt-Bluford is one of them.

The idea seems reasonable. Recognize better workers with extra pay. But it's not that simple. Performance may be easy to measure in some workplaces. But teachers say a classroom is not one of them.

Last year, we reported on a program in Florida to give merit pay to teachers if student scores increase on a statewide test. But a newspaper in Florida now reports that school systems across the state are rejecting the program for a second year.

The Sarasota Herald-Tribune says only about one-third of the school districts in Florida may answer a call for proposals by October first.

Why? Teachers say the program forces them to compete against each other. They say it is unfair to link their pay to results on statewide tests. Also, a high school teacher told the paper that a limited budget means that some top teachers may not be recognized.

Critics say performance-based pay should recognize all that happens in a classroom, not just student performance on tests. All that will do, they say, is get teachers to teach to the test. This is already a concern now that yearly testing is federally required for millions of students.

Attempts at merit pay for American teachers have failed in many cases because of resistance from teachers unions or budget cuts.

Lawmakers in Congress are considering a proposal to provide federal money for performance-based pay. It would give merit pay to teachers who do excellent work in schools in poor areas. But the proposal does not necessarily tie the pay to test scores.

Lawmakers and others point to a successful program in Denver, Colorado. It began in a few schools about eight years ago. Last year it was expanded to all the public schools in the city.

Teachers can earn more by working in unpopular schools or teaching unpopular subjects. They also can earn more by taking classes to improve their teaching, or by raising test scores. The plan also reduces teacher pay if students fail to improve on statewide tests.

A local tax increase pays for the program. Reports from Denver say more teachers are asking to work in lower-income areas. And parents in the Denver area seem to support it.

New programs have begun or are being planned in Minnesota, Maryland and Virginia. But many experts say there is still more to learn about the most effective ways to identify and recognize excellent teachers.

And that's the VOA Special English Education Report, written by Nancy Steinbach. I'm Steve Ember.