A Congressional Committee may hold hearings on a particular bill in order to gather information. These hearings consist of testimony by experts and interested parties giving their views on the bill. Because individuals with conflicting views on an issue will be called to testify, hearings will reveal what information the committee had both for and against passage of the bill.
Hearings have less persuasive value. While the witnesses who testify are often subject matter experts, they are not elected members of congress.
Below is a collection of links to more resources on legislative history, legislative process, and legislative research.