Cluster genealogy is a research

Research

Research can be defined as the scientific search for knowledge, or as any systematic investigation, to establish novel facts, solve new or existing problems, prove new ideas, or develop new theories, usually using a scientific method...

 technique employed by genealogists

Genealogy

Genealogy is the study of families and the tracing of their lineages and history. Genealogists use oral traditions, historical records, genetic analysis, and other records to obtain information about a family and to demonstrate kinship and pedigrees of its members...

 to learn more about an ancestor

Ancestor

An ancestor is a parent or the parent of an ancestor ....

 by examining records left by the ancestor's cluster. A person's cluster consists of the extended family

Extended family

The term extended family has several distinct meanings. In modern Western cultures dominated by nuclear family constructs, it has come to be used generically to refer to grandparents, uncles, aunts, and cousins, whether they live together within the same household or not. However, it may also refer...

, friend

Friendship

Friendship is a form of interpersonal relationship generally considered to be closer than association, although there is a range of degrees of intimacy in both friendships and associations. Friendship and association are often thought of as spanning across the same continuum...

s, neighbors, and other associates such as business partners. Researching the lives of an ancestor's cluster leads to a more complete and more accurate picture of the ancestor's life.

Background

Genealogical

Genealogy

Genealogy is the study of families and the tracing of their lineages and history. Genealogists use oral traditions, historical records, genetic analysis, and other records to obtain information about a family and to demonstrate kinship and pedigrees of its members...

 research begins with a question of identity, relationship, event, or situation. To answer the question, a genealogist gathers and analyzes data from source documents

Primary source

Primary source is a term used in a number of disciplines to describe source material that is closest to the person, information, period, or idea being studied....

 and formulates an answer to the question based on the resulting evidence

Evidence

Evidence in its broadest sense includes everything that is used to determine or demonstrate the truth of an assertion. Giving or procuring evidence is the process of using those things that are either presumed to be true, or were themselves proven via evidence, to demonstrate an assertion's truth...

.

The basic method of research is to gather data from records left by the target ancestor and his or her immediate family. There are several situations, however, where a genealogist wants or needs to use alternate research methods. One such method is cluster genealogy, in which the records left by members of the ancestor's cluster are examined for evidence with which to resolve the question at hand.

Purpose

Cluster genealogy is most often used for the following reasons.

• To break through a "brick wall". In genealogy, a brick wall is a question for which a genealogist has not been able to formulate a satisfactory answer based on the evidence thus far collected. Using cluster genealogy, additional evidence is sought in data gathered from the records left by persons in the ancestor's cluster. For example, if the question is one of place of birth, researching the origins of the ancestor’s neighbors can be helpful. Unrelated family groups often migrated
  Human migration
  Human migration is physical movement by humans from one area to another, sometimes over long distances or in large groups. Historically this movement was nomadic, often causing significant conflict with the indigenous population and their displacement or cultural assimilation. Only a few nomadic...
  
   together or followed earlier migrations of neighbors or family members.

• To build a genealogical proof. When constructing a genealogical proof, it is not sufficient to simply accumulate an assortment of evidence that supports a conclusion. A genealogist must "conduct a reasonably exhaustive search for all information that is or may be pertinent to the identity, relationship, event, or situation in question." (Emphasis added.) It follows that a reasonably exhaustive search will often include a search of records created by persons in the target ancestor's cluster.

• To develop context for an ancestor's life. The facts of an ancestor's life are often meaningful only in the context of his cluster. For example, the fact that an ancestor was a Catholic is interesting; the fact that the ancestor and his family were the only Catholics in their community
  Community
  The term community has two distinct meanings:*a group of interacting people, possibly living in close proximity, and often refers to a group that shares some common values, and is attributed with social cohesion within a shared geographical location, generally in social units larger than a household...
  
  is intriguing.

Further reading

• Lenzen, Connie. "Proving a Maternal Line: The Case of Frances B. Whitney". Originally published in the National Genealogical Society Quarterly, 82, no. 1 (March 1994): 17–31. A case study illustrating the use of the cluster genealogy technique.