Making judgments on priorities in funding is a politican's most difficult task. Scientific information is often necessary to make those judgments, so that good communication between scientist and politican is important. This is, however, difficult because the politician's usual training and working habits are different from those of the scientist. Messages to politicans must therefore be couched differently than in communications between scientists. These messages are more effective when they are concerned with the public need than when they plead for special interests. These messages are most effective when directed to those politicians serving on committees that must deal with the specified issue because Congress makes most political decisions through these committees. Committee members and committee staff members turn to scientists whom they know personally, so that getting to know the members of Congress and the key staff members of committees facilitates communication between science and public policy.