[The following material was taken from, Evidence! Creation & Analysis for the Family Historian, Elizabeth Shown Mills, Genealogical Publishing Co., Inc., Baltimore, MD, 1997.]
Original material, as defined by the purist, is based on firsthand knowledge--be it oral or written. It is the testimony of a person relating events that he or she personally experienced or witnessed. It is an original document created by a party with firsthand knowledge of the information being recorded.
Derivative material is all else. Its weight can span the entire spectrum of reliability--depending upon the form that it takes, the circumstances of its creation, and the skill and reliability of its creator. A debatable hierarchy for appraising derivative material might be: 1) duplicates, 2) transcripts, 3) edited transcripts, 4) abstracts, 5) extracts, 6) compendiums, 7) histories, genealogies, and expository essays, and 8) traditions.
Guidelines for Analyzing Evidence
1) Direct evidence is easier to understand, but indirect evidence can carry equal weight.
2) Reliable genealogical conclusions are based on the weight--not quantity--of evidence found.
3) Evidence should be drawn from a variety of independently created sources.
4) Original source material generally is more reliable than derivative material.
5) The reliability of a derivative work is influenced by the degree of processing it has undergone.
6) The purpose of a record and the motivation of its creators frequently affect its truthfulness.
7) The most reliable informants have firsthand knowledge of the events to which they testify.
8) The veracity and skill of a record's creator will have shaped its content.
9) Timeliness generally adds to a document's credibility.
10) Penmanship can establish identity, date, and authenticity.
11) A record's custodial history affects its trustworthiness.
12) All known records should be used and a thorough effort made to identify unknown materials.
13) The case is never closed on a genealogical conclusion.