Kelly Kaari remembers last year's holiday bonus — it helped to pay for a trip to see Thomas the Tank Engine at a Pennsylvania railroad museum.

"It worked out that we could do a little extra for the kids and the grandparents and the mother-in-law," said Kaari, 33, a project coordinator at Jayeff Construction Corp. in Wall, N.J. "It (a bonus) is able to make Christmas a little bit better."

At Jayeff, bonuses are not just gifts. They are awarded based on merit, said co-founder Jack Zoller. "There is nothing cast in stone that they are going to get a bonus every year."

Jayeff Construction, a firm with 42 employees, is not alone. In a survey by human resources services firm Hewitt Associates, 78 percent of companies said they offer a bonus based on performance, up from 51 percent in 1991. These bonuses often occur at the end of a company's fiscal year, which can coincide with the holidays.

And while merit-based bonuses are rising, traditional holiday bonuses awarded simply out of appreciation are continuing to decline, Hewitt said. In the recent survey, 41 percent of companies said they had such a holiday bonus program.

"We are seeing a gradual shift away from (nonmerit) holiday bonuses," said Paul Shafer, a business leader at Hewitt. "Companies are trying to do what they can to direct the money they do have to high-performing individuals and organizations."

Merit-based bonuses can pay off for employees, more so than a traditional bonus. This year, company spending on such extra pay, as a percentage of payroll, increased to 11.4 percent, up from 9.5 percent in 2004, the Hewitt survey said.

"If employees meet their individual and company goals, they can dramatically increase their compensation, and in most cases, the payout can be well beyond a traditional holiday bonus," said Ken Abosch, a business leader for Hewitt Associates, in a statement.

Zoller said he has offered bonuses since he started the company.

"We do it, hopeful that the employees will appreciate that we do something above and beyond what we have to do," he said. "Most of them can use it at this time of year, paying bills."

Employees at Air Cruisers in Wall get a bonus twice a year, at the end of June and December, in the form of profit-sharings, said Lori Kavanagh, human resources specialist. The amount, which is tied to the company's performance, depends on several factors, including an employee's length of service, she said.

"Bonuses can be pretty good, depending on their years of service and rate of pay," she said.

Bonuses can be more than simply cash.

According to the Hewitt survey of the 41 percent of companies that offer traditional holiday bonuses in 2005, 44 percent will give employees food, such as a turkey or ham, and 37 percent will give retailer gift certificates. Thirteen percent will give cash.

Don Cowan, managing partner at Toms River, N.J., accounting firm Cowan, Gunteski & Co., said his firm gives out Visa gift certificates based on an employee's years of service. Those cards can range from $50 to $500, he said.

"We just feel it is a way of saying thank you to our employees around the holiday time for a full year of service," he said. The firm awards merit bonuses to employees each year after tax season in April, Cowan added.