CGL Data Analysis and Interpretation 2 — Questions and Answers
Question 1: When analyzing a series of census records for an ancestor, you notice the reported age advances by 12 years over a 20-year span. What is the most genealogically sound conclusion?
- The individual lied deliberately about age
- Age reporting in historical censuses was often inconsistent and should be corroborated with other sources (Correct answer)
- The records belong to two different people
- Census enumerators always recorded exact ages
Correct answer: Age reporting in historical censuses was often inconsistent and should be corroborated with other sources
Historical census ages were frequently estimated or misreported, so inconsistencies are common and require triangulation with other sources.
Question 2: A researcher finds a death certificate listing a parent's birthplace as 'Germany' while earlier records say 'Prussia.' How should this discrepancy be interpreted?
- Discard the death certificate as inaccurate
- Treat both as errors and seek a third source
- Recognize that Prussia became part of Germany and the informant may have used contemporary terminology (Correct answer)
- Assume the person had two sets of parents
Correct answer: Recognize that Prussia became part of Germany and the informant may have used contemporary terminology
Political boundaries changed over time, and informants often used current country names rather than the historic jurisdiction.
Question 3: Which statistical concept is most useful when evaluating the likelihood that two individuals with the same name in the same county are the same person?
- Standard deviation
- Name frequency analysis combined with cluster research (Correct answer)
- Regression analysis
- Chi-square testing
Correct answer: Name frequency analysis combined with cluster research
Name frequency analysis alongside cluster research of associated individuals helps assess whether two same-name records refer to one person.
Question 4: In a DNA segment analysis, a genealogist finds a 7 cM shared segment between two individuals. What is the best interpretive approach?
- Conclude they share a great-grandparent relationship
- Treat the segment as definitive proof of a specific relationship
- Use it as a weak lead requiring additional evidence, as small segments may be identical by chance (Correct answer)
- Ignore the segment entirely
Correct answer: Use it as a weak lead requiring additional evidence, as small segments may be identical by chance
Segments below approximately 10 cM carry a higher risk of being identical by chance (IBC) and should not be relied upon alone for relationship conclusions.
Question 5: A genealogist is correlating land records that reference metes-and-bounds descriptions across three deeds. What is the primary analytical goal?
- Determine the monetary value of the property
- Reconstruct the physical location and ownership chain of the parcel (Correct answer)
- Identify the surveyor's identity
- Calculate acreage for tax purposes
Correct answer: Reconstruct the physical location and ownership chain of the parcel
Correlating metes-and-bounds descriptions across deeds allows reconstruction of ownership sequences and physical property boundaries.
Question 6: When presenting DNA evidence to a lecture audience, which approach best illustrates sound data interpretation?
- Show only the matching segments without discussing limitations
- Present shared cM values alongside relationship probability ranges and note alternative relationships (Correct answer)
- Claim the highest-probability relationship is definitive
- Avoid discussing DNA entirely due to complexity
Correct answer: Present shared cM values alongside relationship probability ranges and note alternative relationships
Responsible DNA interpretation requires presenting both the match data and the full range of probable relationships, acknowledging uncertainty.
Question 7: A cluster analysis of a brick-wall ancestor's DNA matches reveals that one group of matches all descend from a specific couple. What does this most reliably indicate?
- The brick-wall ancestor is definitely a child of that couple
- The brick-wall ancestor shares ancestry with that couple's line, warranting focused research into those descendants (Correct answer)
- All members of the cluster are the same person
- The couple is unrelated to the brick-wall ancestor
Correct answer: The brick-wall ancestor shares ancestry with that couple's line, warranting focused research into those descendants
Clustering identifies shared ancestral lines but does not pinpoint the exact relationship; it directs further targeted research.
CGL Data Analysis and Interpretation 2
When analyzing a series of census records for an ancestor, you notice the reported age advances by 12 years over a 20-year span.
What is the most genealogically sound conclusion?