Limitations of Record Indexes

Why you can't always rely on the index to find your ancestor


Indexes to genealogically significant records appear to be invaluable tools for genealogists. However, they all have certain limitations in common due to the fact that the indexer is between the researcher and the original record. The accuracy of any index can be negatively limited by the following:


  • The physical condition of the original record
  • The accuracy of the original record
  • The ability of the indexer to decipher the original record
  • The ability of the indexer to transcribe the information in the record
  • The scope of the index
  • The ability of the researcher to use the index

It occurs to me that the issue does not lie with the index but with the researcher. Unless the researcher understands and compensates for the limitations of an index, his or her work product will always be suspect and incomplete.


The main challenge of indexed records is analyzing and identifying the the terms to include in the indexed listing. The move from paper-based indexing systems, such as the word index in the back of a book, to the computer based systems has not significantly changed the process. Genealogical indexes focus primarily on names, dates and places. The major flaw in any such system revolves around the fact that all three major search categories can and do change from document to document and still refer to the same historical individual. Computer based search engines have evolved in two separate directions; those search engines that do string searches, i.e. compare sequences of characters and those that locate documents etc. by looking at selected terms.


For example, if I wanted to find an ancestor whose name was Elizabeth Brown, I might find the following variations in the name "Elizabeth" quoted from the Behind the Name website:


VARIANTS: Elisabeth, Elsabeth, Elyzabeth (English), Elisabeth (Biblical)
DIMINUTIVES: Bess, Bessie, Beth, Betsy, Bette, Bettie, Betty, Buffy, Elisa, Eliza, Ella, Ellie, Elly, Elsa, Elsie, Elyse, Libbie, Libby, Liddy, Lilian, Lilibet,Lilibeth, Lillia, Lillian, Lisa, Lise, Liz, Liza, Lizbeth, Lizette, Lizzie, Lizzy, Tetty, Bettye, Elle, Leanna, Leesa, Liana, Liliana, Lilliana (English)
OTHER LANGUAGES: Zabel (Armenian), Elixabete (Basque), Elisabet (Biblical Greek), Elisheba (Biblical Hebrew), Elisabeth (Biblical Latin), Elisaveta (Bulgarian),Elizabeta (Croatian), Alzbeta, Eliska (Czech), Elisabet, Elisabeth, Isabella, Eli, Elise, Ella, Else, Lilly, Lis, Lisa, Lisbet, Lise, Lissi (Danish), Elisabeth, Isabella, Isabelle, Betje,Elise, Elly, Els, Else, Elsje, Ilse, Isa, Lies, Liesbeth, Liese, Liesje, Lijsbeth, Lisa (Dutch), Eliisabet, Liis, Liisa, Liisi, Liisu (Estonian), Elisabet, Eliisa, Elisa, Ella, Elsa, Liisa,Liisi (Finnish), Elisabeth, Isabel, Isabelle, Babette, Elise, Lili, Lilian, Liliane, Lilianne, Lise, Lisette (French), Bet, Lys (Frisian), Sabela (Galician), Elisabed, Eliso (Georgian),Elisabeth, Isabel, Isabelle, Bettina, Elisa, Elise, Elli, Elsa, Else, Ilsa, Ilse, Isa, Isabell, Isabella, Lies, Liesa, Liese, Liesel, Liesl, Lili, Lilli, Lisa, Lisbeth (German),Elisavet (Greek), Elikapeka (Hawaiian), Elisheva (Hebrew), Erzsebet, Izabella, Bozsi, Erzsi, Lili, Liliana, Liza, Zsoka (Hungarian), Elisabet (Icelandic), Eilis, Eilish, Isibeal,Sibeal (Irish), Elisabetta, Isabella, Elisa, Elsa, Isa, Liana, Liliana, Lisa (Italian), Bet, Betje (Limburgish), Elzbieta, Elze (Lithuanian), Elisaveta, Beti, Veta (Macedonian),Ealisaid (Manx), Ibb (Medieval English), Isabel (Medieval Occitan), Elisabet, Elisabeth, Isabella, Eli, Elise, Ella, Else, Lilly, Lis, Lisa, Lisbet, Lise, Liss (Norwegian),Isabel (Occitan), Elzbieta, Izabela, Izabella, Ela, Eliza, Liliana (Polish), Isabel, Belinha, Elisa, Elisabete, Isabela, Liana, Liliana (Portuguese), Lilian (Portuguese (Brazilian)),Elisabeta, Isabela, Isabella, Liana, Liliana (Romanian), Elizaveta, Yelizaveta, Liza, Lizaveta (Russian), Ealasaid, Elspet, Elspeth, Iseabail, Ishbel, Isobel, Beileag, Lileas,Lilias, Lillias (Scottish), Jelisaveta, Jela, Jelica (Serbian), Alzbeta, Eliska (Slovak), Elizabeta, Spela (Slovene), Isabel, Ysabel, Eli, Elisa, Elisabet, Isa, Isabela,Liliana (Spanish), Elisabet, Elisabeth, Isabella, Elise, Ella, Elsa, Lilly, Lis, Lisa, Lisbet, Lise (Swedish), Yelyzaveta (Ukrainian), Bethan (Welsh)


Which of these will be found by either a computer string search or a selective indexing program? It is not unusual, in documents dating from before 1850, to have the same person's name spelled different ways in the same document. Depending on the particular online program involved, the search engine may or may not be sophisticated to realize that all of these types of variations are included in the category of "Elizabeth" names? Likewise, the genealogy researcher may not be sophisticated or even aware of the variety of names that can be included within one common designation. This is particularly true as pointed out by the example above, when you cross linguistic lines.


This issue is further complicated by the fact that the person's name could have actually been a derivative of Elizabeth, but she was never named Elizabeth. The child could have been named "Betty" for example at birth.


When you add dates and names to the mix, the complexity of indexing becomes apparent.


So how does anyone find anything? As I have noted before, searching is an involved and complex skill. It is acquired by practicing through trial and error. But there are several rules that help to expedite the process. Here are some of my own rules for searching.


  • Never rely solely on an index for information about an ancestor
  • Always try to view the original record found through an index
  • If there is a basis for assuming that an ancestor should have appeared in a record; search the record page-by-page and entry-by-entry
  • Disregard traditional spelling assumptions
  • Start from what you know for certain and don't make any assumptions about the data
  • Look for and accept name variations


Let me give one example. Let's suppose you are looking for you ancestor in the U.S. Federal Census Record. You could rely on an index and assume that failure to find the ancestor in the index indicates that he or she was not included. This is possible. But it is always more likely that one or more of the following occurred:


  • The original name was spelled differently than you expected it to be, i.e. you are searching for the wrong name
  • The indexer misread the name
  • The indexer omitted the name altogether
  • You are searching in the wrong place or the name of the place has changed


Assuming you think you are searching for the "right" name, you conclude that the person is missing from the census. Here is the first question: why are you searching for the name of the person?


What makes you think your selection of the name is correct? Here is where I get to the point I made above about the issue being with the researcher and not the index. An index is an index even one that searches every word in the document. As a researcher, you need to compensate for the limitations of the indexing process and do your own searches. Yes, you may have to search the documents page-by-page and word-by-word. This can be a challenge but is the only way to be completely assured that you are relying on the only the original information.


Why won't this work all the time? There is always the chance that the information you are searching for is not in the particular record you have selected. My experience is that most commonly, you have been searching in the wrong place. Unfortunately, I cannot give you the experience you need to become a better searcher. Skill in searching only comes from doing searches over and over again.


Written by James L. Tanner. Used with permission.


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