By Julia Morse
When a thorough search of all available records fails to provide the desired genealogical answers, professional genealogy researchers often employ “cluster research” in order to methodically uncover the mystery. Constance Knox of “Genealogy TV” calls cluster research “the #1 way to break down brick walls” .
Cluster research techniques call for you to cast a broader net for clues. Cluster research is often called “FAN Club” research, a term first coined by professional Elizabeth Shown Mills. FAN stands for Friends, Associates, and Neighbors, reminding us of the people who may have connections with our person of interest, whom we will study in order to look for leads and patterns that ultimately point to new information or hypotheses. , 
If this sounds familiar, you may already be practicing key elements of the FAN Club strategy, particularly if you normally perform “Whole Family” and community research rather than sticking exclusively to direct-line ancestral families.
Extended family are included in the “Friends” category. With this technique, you also make note of “Associates” such as others in the community associated by occupation or church participation. Witnesses on legal documents should also be included in the FAN Club list. Of course a list of “Neighbors,” can often be extrapolated from census pages adjacent to your target ancestor.
A very common example would be examining neighboring families (usually from census data) to search for ties. Particularly in the 1800’s and earlier, it was very common for related families and close friends to migrate together. Also, in rural and small communities, there is a high probability that marriage partners came from families living in walking distance proximity. If the maiden name of an ancestor is elusive, you may not realize until you dig further that in-laws or cousins were living nearby.
It is very common for related families to follow each other as they migrate to new regions. If you can find that associates and neighbors came from the same previous geographic location, that can suggest a special relationship or kinship. Or, it could suggest a previous residence that provides a new location for records searches.
The idea of “cluster research” is to methodically compile a list of all the names that have this connection with your target ancestor. This is called your target ancestor’s “FAN Club.” Then analyze the “FAN Club” list to prioritize and hypothesize relationships of interest. Finally, methodically research each one.
Professional genalogists are particularly structured and deliberate in their approach to cluster research, logging all research data in a “research log,” very often in a sortable spreadsheets. The spreadsheets aid in sorting and filtering for commonalities among associated persons. Other graphing and schematic techniques may be used to examime and hypothesize relationships.
Learn More about Cluster Research
Most people recommend learning about cluster research from case examples. I have found the following resources helpful:
(A) “Locating Your Ancestors Using Clusters,” a 55-minute practical video introduction to cluster research by by James Tanner as part of the BYU Family History Library Webinar Series: https://youtu.be/FSElDcp4ySo.
(B) Case Study by Elizabeth Shown Mills: “QuickLesson 11: Identity Problems & the FAN Principle”, Evidence Explained: Historical Analysis (blog). Elizabeth steps through an example of applying FAN principles.
(C) “How to Use the FAN Club in Research,” an audio podcast from Family Locket Genealogists:
- Part 1 – Examples of FAN Club/Cluster Research, including different types of FAN associations found in common records. https://youtu.be/LYJfys5cCpQ (16 min.)
- Part 2 – Case Study explaining step-by-step their research method, including how they used spreadsheets to log and sort information. https://youtu.be/LYJfys5cCpQ?t=960 (16 min.)
(D) Case Study by Justyna Cwynar (video). She used the witness of Prussian Baptismal records to hypothesize relatives, eventually confirming with DNA:
(E) “Cluster Research” YouTube Video Playlist on “Genealogy TV” channel, by Constance Knox, https://www.youtube.com/playlist?list=PLiMXWjHlj5RQKQsBOzVta7lN167GBHeb9. In particular, Connie provides her method of copying census data pages into Excel and using the automatic filter to isolate males or females with a particular family name: https://youtu.be/wnI8Np_J4WE.
(F ) “Creating a Research Plan for Cluster Research,” a video webinar from AmericanAncestors (by the New England Historic Genealogy Society). Lindsay Fulton, Director of Research Services, presents a step-by-step explanation of careful, robust techniques used by professional researchers to plan and execute effective cluster research for difficult genealogical mysteries. The presentation begins with extensive ideas for records that can be pursued to develop FAN Club associates of interest:
 Constance Knox, “#1 Way to Break Down Brick Walls: Updated (2020)” (Video), YouTube Channel “Genealogy TV,” 16 Oct 2020, https://youtu.be/wnI8Np_J4WE.
 Tony Proctor, “FAN Principles Unfolded,” Parallax View (Blog), 16 Nov 2016, http://parallax-viewpoint.blogspot.com/2016/11/fan-principles-unfolded.html
 Constance Knox, “Cluster Research” (Playlist), YouTube Channel “Genealogy TV,” 12 Feb 2021, https://www.youtube.com/playlist?list=PLiMXWjHlj5RQKQsBOzVta7lN167GBHeb9.