Genealogists naturally analyse and compare records to figure out who is whom in a family. Rarely does a genealogist write down how they learn family relationships. When one county has six men named John Smith, a carefully researcher will do analysis to figure out which is the correct John Smith. If this mental reasoning is not written down, the next researcher is doomed to do the research over again. Learn how to write brief proof summaries so the next generation of researchers know how you reached your conclusions.