What are the four different factors that decide what committee a congressman will join

STANDING COMMITTEES, which continue from one Congress to the next, are probably the most important type because they consider and shape the vast majority of proposed laws. Standing committees can be combined or discontinued but most of them have been around for many years. Standing committees also conduct investigations, such as the Senate Banking Committee's investigation of President Bill Clinton's Whitewater investments.SELECT COMMITTEES are temporarily formed for specific purposes, often to study a particular issue. They usually do not draft legislation. Some, like the select committees to investigate the assassinations of John F. Kennedy and Martin Luther King, are obviously intended to have limited lives. Others, like the Select Committee on Aging and the Select Committee on Indian Affairs, have existed for a number of years actually produce legislation. Sometimes long-standing select committees eventually become standing committees.JOINT COMMITTEES have similar purposes as select committees, but they are made up of members from both the House and the Senate. They are set up to conduct business between the houses and to help focus public attention on major issues. Some joint committees handle routine matters, such as supervising the Library of Congress.CONFERENCE COMMITTEES are specially created when the House and the Senate need to reconcile different versions of the same bill. A conference committee is made up of members from the House and Senate committees that originally considered the bill. Once the committee agrees on a compromise, the revised bill is returned to both houses of Congress for their approval.