There are some hidden assumptions when we ask the question "Which one of these records belong to my grandfather?" I'll make these explicit because we can often lead ourselves astray when we are hot on the trail of new information.
- We assume that the record set that we're looking at is complete, and that if our research subject should have had a record of this type, he must be in that database. Consider the possibility that you might be looking at the records of two other people, and neither one is your grandfather.
- We forget to check the dates of coverage in the database, and if there were a record for our research subject, it would have been made before or after these records were created.
- We don't know how common or uncommon names are, and assume that there can't be that many people with the same name in the same place.
- We assume that if we find one source, that source by itself is enough to be 'proof'.
One of the ways to get a fresh perspective is to realize that although our goal is to find information about our family members or research subjects, when we search for information, we are looking for records, not people. Crista Cowan of Ancestry.com demonstrated how this can affect our search in a recent video, Smarter Searching: Search for Records, Not People.
Once we have the record in hand, it is helpful to focus on the source itself, with no fixed notion of any person it might belong to, and analyze what it is telling us, and how accurate the information is likely to be. Elizabeth Shown Mills' QuickLesson 17: The Evidence Analysis Process Map explains the process.
There are three ways to analyze what you are looking at, and the answers to each point can be classified in three different categories, which has earned the process map the nickname of "the 3 x 3".
- We look at the source to see what type of source it is. (Original / Derivative / Authored)
- We look at the information contained in the source to see what quality of information it might be. (Primary / Secondary / Undetermined)
- We look at how well the information answers (or doesn't answer) the research question we ask. (Direct / Indirect / Negative)
Follow the link for her full explanation and a case history -- I'll quote one section because Mills' explanation is far more succinct than mine would be:
The Evaluation Process
This process — the analysis of the source, its information, and the
evidence we draw from it — is only the first step toward a conclusion.
It is a step we repeat over and again, as research progresses.
Conclusions, on the other hand, must be based on the whole body of
evidence that we assemble. In the evaluation stage, which we should
also repeat each time we make new findings, we weigh
- the quality of each source against the other;
- the credibility of each piece of information against the other; and
- the strength of each piece of evidence against the other.
We correlate details. We compare and contrast them in a search for
patterns, dissimilarities, or conflicts that could strengthen or
weaken a conclusion. If we have multiple pieces of evidence pointing
to a conclusion, we consider whether each piece of underlying
information is independently created—or whether all might be tracked
back to a common source. It is also at this point, if we are
genealogists, that we apply the Genealogical Proof Standard* to
measure the strength of any hypothesis we might be forming.
*“The Genealogical Proof Standard,” Board for Certification of Genealogists (www.bcgcertification.org/resources/standards.html : last
accessed 1 August 2013). See also Thomas W. Jones, Mastering
Genealogical Proof (Arlington, Va.: National Genealogical Society,
The five points of the Genealogical Proof Standard are:
- a reasonably exhaustive search
- complete and accurate source citations
- analysis and correlation of the collected information
- resolution of any conflicting evidence
- a soundly reasoned, coherently written conclusion
Doing a reasonably exhaustive search includes, in part, looking at the available pool of records and discovering that yes, there might be several people with the same name as your grandfather.
Source citations help you remember where the information came from, which becomes really, really important as you collect more and more information. It also allows other researchers to 'look over your shoulder' and see what you are looking at.
Analyzing and correlating your collected information helps you realize that (for example) two of the records you're looking at belong to the same person because they both have the same service number on them.
Resolution of the conflicting evidence -- this step is where you consider that your grandfather might have lied about his age in order to join up sooner, or that the person writing down the information might have back-calculated the year of birth from the age and that the record is inconsistent with itself.
Attempting to write out a proof statement is useful because it helps reveal things that you missed in your analysis, or makes you think of questions that you still haven't answered.
It seems like a lot of work, but the more you practice the individual steps in the process, the more it becomes second nature.
To compare the information from a set of sources, some researchers write summaries of the information on index cards so they can shuffle them around to see which records agree on different points, others like spreadsheets or tables, and some use mind-maps.
My standard way of working is to assume that all the records I collect belong to different people, until I can find a way to prove that assumption is wrong; I let the information in the forms drive me toward a resolution, instead of starting with the conclusion and then trying to explain away why the information doesn't match what I expected it to be. See the question How would you handle a census record that is almost certainly the target family but which has too many discrepancies? for an example of writing out the differences between records in table format.