When it was recently released, I read Elizabeth Shown Mills’s latest online lesson, “QuickLesson 10: Original Records, Image Copies, and Derivatives.” While we often speak of sources as being originals or derivatives, real life is not always that tidy. Mills presents three caveats to consider when classifying a source. One thing that can be done is to distinguish between formats that preserve the original content and those that process the content and the form of the content. Mills lists about 10 of each type.
I want to emphasize the characteristics of one of the derivative types she presents: indexes.
I regard indexes (as they are called on FamilySearch.org) and databases (as they are called on Ancestry.com) as nearly the worst of all derivative types. Indexes are used as finding aids. To that end, publishers apply all sorts of treatments to the information found in the original records. The information originally in the records is interpreted and transformed, and conclusions are drawn. Some of these are made by keyers and indexers. Some are applied en masse by computer algorithms.
- Names. Name parts are divided into given and surnames, sometimes incorrectly, even swapped. Indexers might be instructed to interpret abbreviations. Keyers and indexers misread names. You should also be aware that to increase findability, publishers standardize names—behind the scenes “Jack” becomes “John” and so forth.
- Dates. Dates are often assumed to be Gregorian, regardless. Or dates from other calendar systems may be forced into Western Calendar format.
- Birth Dates. Birth dates may be inferred from age. Birth years calculated this way for a June 1 census are wrong over half of the time.
- Places. Abbreviations may be interpreted by indexers or computers. Indiana’s “Ia” may become Iowa and its “In” may become India. Place names may be forced into a hierarchy of three jurisdictions (town, county, state for the U.S.) regardless of reality. As with names, publishers standardize place names behind the scenes, sometimes using pick lists, making it impossible to find some records.
- Race. Race, color, nationality, and ethnicity may be confused, standardized, and reduced to pick lists that exclude and confuse many values.
The next time you use an index, remember these shortcomings. Indexes should be considered finding aids. When available, always view the image. When images are not available, always use the index information to obtain copies of the original record.
The other nine lessons can be found on the website Evidence Explained: Historical Analysis, Citation & Source Usage.