The review also will consider the impact of a potential policy repeal on morale, unit cohesion and retention, he said.

Gates attempted to allay concerns within the House Armed Services Committee that the working group he announced yesterday will overlook getting input about a potential policy change from the troops themselves.

Gates said the working group, headed by Jeh Johnson, the Pentagon’s top lawyer, and Army Gen. Carter Ham, the commander of U.S. Army Europe, will review the full range of issues associated with a repeal to ‘‘Don’t Ask, Don’t Tell.”

‘‘One of the purposes of the review that I have directed to be undertaken by General Ham and by Jeh Johnson is precisely so we can understand not just the views and concerns of the service chiefs, but of our military people and their families,” he said.

‘‘If you want lasting and effective change, you had better bring the people who are going to be affected by it into the discussion and get their views,” Gates said. ‘‘At a minimum, it will help you mitigate whatever negative consequences there are.”

The panel also will evaluate the impact of a policy change on military readiness and effectiveness, Gates said, including unit cohesion, morale, and retention, ‘‘so we can get some facts into this debate, or at least some data that we think is reliable and objective.”

As part of that, Gates said he will ask the Rand Corporation to update its 1993 study that led to the policy’s adoption, expanding the review to cover a broader range of issues.

‘‘I think this review period is absolutely essential in terms of us understanding what we're doing; figuring out what the concerns are and the issues are, helping us figure out how to mitigate them so that if the Congress does vote to change this policy, we have an understanding of how to go about implementing in a way that minimizes whatever negative consequences there are,” Gates told legislators.

‘‘We have set the goal,” he said, emphasizing that the decision ultimately will be Congress’ to make.

Should Congress change the policy, Gates said, it’s ‘‘vitally important” to be able to tell servicemembers that the change represents the view of the elected representatives of the United States of America.