NEW YORK – Teacher professional development is expensive for public schools. In many states, laws require teachers to continue to take college graduate classes and earn at least a master’s degree within a certain number of years.

Because of that requirement, many teachers unions have insisted that schools reimburse teachers for the cost of tuition. And most school districts hand out automatic raises to teachers for reaching benchmarks in their graduate work, generally for every 15 credits earned.

MORE NEWS: Know These Before Moving From Cyprus To The UK

But Newsday recently published an in-depth study of the type of graduate courses that teachers in Long Island public schools have been taking. It turns out that many of the courses are trivial in content and offer nothing that help teachers become more effective in their duties.

Credits earned for classes like yoga, fencing, volleyball and stress management have been counted by school districts toward automatic raises, according to Courant.com, which published a synopsis of the Newsday study.

“Newsday observed classes where teachers colored with crayons, made flip books out of construction paper and discussed Australian cheeses,” the news report said. “Book clubs, trips overseas and volleyball basics have all led to raises.”

But schools still give big raises to teachers who take many of these useless classes.

In Long Island public schools, a typical raise is about $2,000 to $2,500 per year for every 15 credits earned, according to the news report. Those costs add about $80,000 to $100,000 per year to the payroll of smaller school districts and up to $1 million per year for larger districts.

Are the extra costs worth it?

MORE NEWS: How to prepare for face-to-face classes

Newsday reportedly obtained records from 44 school districts detailing 59,000 courses taken by teachers in those schools over a five-year period. An in-depth analysis was performed on roughly 2,000 courses taken by teachers in 11 districts.

A minimum of 100 courses “had little connection to student learning and were of questionable academic value,” the news report said. “School districts also approved more than 750 courses outside a teacher’s subject area.”

Many employees who are not teachers also received raises for taking professional development classes.

Only 40 of Long Island’s 125 school districts have limits on the number of courses that can be taken in a year. That has allowed many teachers to take a lot of classes that have nothing to do with improving their skills and earn big raises in a hurry.

For instance, one Middle Country school district teacher earned enough college credits in 15 months to increase her salary by more than $17,500 per year, the news report said.

“When you multiply it by all the teachers in the district, the cost is in the millions,” said Terry O’Neil, an attorney who represents many Long Island school districts. “The issue is, what are you getting for your bucks?”

Not much of anything, as far as we can see. This system of giving salary increases for taking silly classes is just another way to funnel extra resources to teachers at a time when schools can least afford it.

Some studies have even suggested that legitimate college classes, designed to help teachers improve in the classroom, have little or no impact on teacher or student performance.

Meanwhile many schools continue to lay off younger teachers or cut student programs, while still forking out raises for teachers to take meaningless college classes.

It’s time for the mass giveaway to end, particularly when the same money could be used to help K-12 students learn and advance.