Ruppersberger said authorities were considering a proposal to require a declassification review of any FISA Court decision order or opinion "to improve transparency without threatening sources and methods."
The FISA Court grants or refuses surveillance rights requests from U.S. government agencies.
Meanwhile, Sen. Patrick Leahy, D-Vermont, and Rep. James Sensenbrenner, R-Wisconsin, introduced legislation to limit the NSA's collection and analysis of cell phone calls and emails.
It was an about-face for the two men, who were the leading authors of the Patriot Act in the wake of the September 11 attacks.
Alexander, the NSA director, said that of the billions of records of personal data collected last year by the agency, just 288 of them were reviewed.
And technical safeguards exist to ensure that the data are not available to non-authorized personnel, he said.
Only 22 people at NSA are authorized to look at certain phone numbers, he said, and about 30 are authorized to look into the database that contains those numbers.
Referring to the unauthorized release of documents about the NSA's activities, he said, "Nothing that has been released has shown that we are trying to do something illegal or unprofessional; when we find a mistake, a compliance issue, we report it to this committee, to all our overseers, and we correct it."
In his testimony Tuesday, Clapper noted that he had ordered the declassification of a series of documents in recent months to inform the public debate on the matter, and would continue to do so.
"These documents let our citizens see the seriousness, the thoughtfulness and the rigor with which the FISA court exercises its responsibilities," he said, adding that the NSA comprises "honorable people."
Though changes must be made, he urged lawmakers to "remain mindful of the potential long-term impact of overcorrecting."
Most of the documents released by Clapper date to 2009, when the administration was pushing lawmakers to reauthorize sections of the Patriot Act that were set to expire.
Most of the newly declassified documents describe the aggressive push by the NSA, FBI and the Justice Department for lawmakers to save the bulk telephone data collection effort, known as the 215 program, because it was important for their efforts to thwart terrorist threats.
The collection of mobile phone data, or metadata -- including numbers called and date, time and length of calls -- began in 2006 and matched the NSA's collection of land line telephone data.
At the same time, lawmakers were urged not to discuss the classified program for fear it would hurt national security, the documents say.
This year, after Snowden released the cache of classified documents, including court orders detailing the 215 bulk data program, many lawmakers said they were shocked about the extent of the program.
On Tuesday, Clapper said he wasn't buying their reactions. "It reminds me of 'Casablanca,' " Clapper said, referring to the movie from the 1940s. "My God, there's gambling going on here."