In the field of genealogy, the conclusion to a research question is considered proven when it meets the Genealogical Proof Standard (GPS). The GPS consists of five interdependent elements, each of which plays a role in ensuring a conclusion is credible:
- Reasonably exhaustive research
- Complete and accurate source citations for each information item
- Analysis and correlation of sources, information items, and evidence
- Resolution of conflicts among evidence
- A sound, coherent, written conclusion 
Case studies published in the National Genealogical Society Quarterly (NGSQ) present conclusions that meet the GPS—usually in response to research questions of relationship, identity, or circumstance. An example is “One George Deane or More? Determining an Identity Spanning Illinois, Iowa, Kansas, and Missouri, but not Wisconsin,” by Darcie Hind Posz, CG, published in the September 2015 issue of NGSQ. This case study demonstrates how the five elements of the GPS work together to establish a reliable, proven conclusion.
Posz’s case study focuses on the fate of George C. Deane of Adams County, Illinois, who parted ways with his wife, Minnie, and their daughter, Jessie, in 1889. Family lore indicates George was killed in 1891. A man named George Deane, husband of Susie Deane, died in Woodbury County, Iowa, in 1891 after being struck by a train. Posz’s comprehensive research, careful analysis, and presentation of evidence meet the GPS and support her conclusion that these men were one and the same.
Reasonably Exhaustive Research
Posz presents information from a variety of sources, including family records, tombstone inscriptions, military and vital records, probate files, federal and state censuses, historical compilations, deeds, newspapers, and funeral home records. She documents negative searches, communicating to readers that key sources were searched unsuccessfully. In some cases, she incorporates negative evidence derived from those searches. Her reasonably exhaustive research minimizes the likelihood that new evidence will overturn her conclusion. If additional sources or information related to this family are discovered in the future, they will likely provide evidence that supports, rather than refutes, her conclusion.
Posz’s case study—and all NGSQ case studies—include complete source citations for each piece of information presented in the text. Source citations allow readers to understand the breadth of the research, determine whether it was reasonably exhaustive, and identify whether high-quality, independent sources were used.
Analysis and Correlation
Posz’s case study includes an in-depth analysis of the facts presented, and correlation and comparison of known details about George of Illinois and George of Iowa. She carefully analyzes the dates that various events occurred in both men’s lives, and offers explanations that tie together the similarities between the men. Sound analysis and correlation ensures that her conclusion is a reflection not only of the information discovered, but also of how those pieces of information fit together as evidence.
Resolution of Conflicts
As information is gathered in an effort to answer a research question, it is possible that some evidence may conflict with the solution offered by the author and point to a different conclusion. In cases such as these, conflicts must be brought into the discussion and resolved for the author’s proposed solution to be considered credible. In some cases—such as Posz’s case study—no conflicting evidence exists and thus, no such discussion is necessary.
The conclusion to a research question can be considered proven when a written body of work demonstrates reasonably exhaustive research, incorporates source citations, provides analysis and correlation of evidence, and resolves conflicts among evidence. Posz’s written conclusion allows her to demonstrate that she has met the necessary elements of the GPS. Most importantly, it affords her the opportunity to explain how the information she discovered provides evidence that supports her conclusion.
The five elements of the GPS are interdependent and must all be addressed to establish a reliable conclusion. When followed, the GPS provides genealogists with the framework necessary to establish proof in their own research and determine the reliability of others’ conclusions.
Many opportunities exist for genealogists to learn how to apply the GPS. The National Genealogical Society’s Special Topics Series includes the text Mastering Genealogical Proof, a comprehensive guide to genealogical methods and reasoning authored by Dr. Thomas W. Jones, PhD, CG, CGL, FASG, FUGA, FNGS. Additionally, the GenProof Study Group offers a valuable opportunity for in-depth, chapter-by-chapter study of the textbook.
 Genealogy Standards: Fiftieth Anniversary Edition, Kindle edition (New York, New York and Nashville, Tennessee: Ancestry.com/Turner Publishing Company, 2014), 239.