The way NBA referees are evaluated and instructed to call games is being scrutinized in light of the FBI investigation of Tim Donaghy for allegedly betting on games.

"Perhaps this situation brings to light that folks need to go back to the drawing board," National Basketball Referees Association spokesman Lamell McMorris said.

Donaghy, a 13-year NBA referee, resigned July 9. Commissioner David Stern addressed the crisis Tuesday at a news conference in New York. Stern pointed out that the league employs 30 observers, one for each NBA city. The observers critique referees' performances, and four group supervisors audit the observers.