Not all legislative history documents are created equal. The following is a list of the relative weight (authority or persuasiveness) of each document type from highest to lowest:
Committee Reports are generally considered to be the most useful documents for determining legislative intent because they are written by the committees that work intensively on the bills that the reports accompany. They may contain explicit point-by-point expressions of intent and may also include majority and minority views.
Of slightly less weight are:
Even less weighty but still potentially useful are:
Finally, Presidential Signing Statements are part of a legislative history but rarely add anything of value since they express the views of the Executive rather than those of Congress.
The publications by which committees report to the Senate or House as a whole concerning the findings of their hearings and deliberations on bills reported out of committee. Reports usually include the text of the bill, analysis of each section, explanation of the committee's reasoning on every significant point, as well as recommendations and other information related to the enactment of the bill. Often considered the most authoritative of the legislative history documents.
Prepared by committee staff, agency specialists or private consultants. Their purpose is to provide background information to committees concerning issues that may become the focus of legislative attention and to assist policy formulation.
When bills are introduced, they are referred to the committee having jurisdiction over that area of legislation. Often, the committee will hold public hearings to gather opinions and information regarding the legislation. Many witnesses prepare valuable and well-documented presentations, including analysis from uniquely informed perspectives.
Hearing documents include:
Transcripts of House and Senate floor debate by legislators on specific bills.
Proposed legislation by the House or Senate. Usually, several versions of a bill are generated as it works its way through the legislative process.
Statements issued by the President which sometimes accompany bill signings. Since the President is not a member of the legislative body, a presidential signing statement is considered very indirect evidence of intent at best.