The stress tests have been criticized by some banks because the central bank has kept secret the full details of the computer models it is using to evaluate each bank. The Fed has defended this practice. It has argued that it is similar to teachers not giving students specific questions that will appear on a test to guard against students memorizing the answers.
"We hear criticism from bankers that our models are a 'black box' which frustrates their efforts to anticipate our supervisory findings," Bernanke said. He said that over time, the banks should better understand the standards the tests are measuring.
In this year's test, the Fed approved dividend payment plans and stock repurchase plans for 14 of the 18 banks outright.
Two of the banks, JPMorgan Chase and Goldman Sachs, were told by the Fed that they could proceed with their plans but would need to submit new capital plans. Two other banks, Ally Financial and BB&T, were forbidden by the Fed to go through with their dividend increases and share buybacks.
Ally Financial, the former financing arm of General Motors, fared the worst on the stress test. The Fed's data showed that Ally's projected capital level was below the minimum the Fed thinks a bank would need to survive a severe recession. Ally officials said they believed the Fed's testing models were unreasonable.
BB&T, based in Winston-Salem, N.C., said it would resubmit its capital plan and that it believes that it will be able to address the factors which had led to the Fed's objections.
Associated Press reporter Ray Henry in Atlanta contributed to this report.