Some people eat, sleep and chew gum, I do genealogy and write...

Tuesday, September 4, 2012

IGI, PRF and AF -- What are they really?

For a long time,'s main draw was the ability to search three huge databases of information about families and individuals; the Ancestral File (AF), the Pedigree Resource File (PRF) and the International Genealogical Index (IGI). Then it appeared that these three resources had vanished when the site was upgraded in December of 2010. I still talk to people bemoaning the loss of the old website and the loss of these files.

Actually, all three resources continued to be available on the new site, however part of the IGI was not included in the upgrade. Recently, the last component of the IGI was added back into the revised website. So where are they? And how can you search the records? But, more importantly, why would you want to do so? And what good are they?

First you need to understand what these records are and where they came from. It might also help to know their limitations.

The Ancestral File
If you want to know anything about these files, the first place you should look is the FamilySearch Research Wiki. This extensive collection of articles about genealogy gives in depth information about each of the resources and just about everything else in the genealogical world. Here is a quote from the Research Wiki on the Ancestral File:
Ancestral File is a computerized collection of genealogies that links families into pedigrees, showing ancestors and descendants. It contains information for about 40 million people from throughout the world. It shows individuals’ names, family relationships, dates and places of birth, marriage, and death. Ancestral File was created from thousands of user submitted pedigree charts, family group sheets, and GEDCOM files. Submissions were merged to eliminate duplication and submitted corrections were applied to eliminate errors.

  • The current site contains 40 million, 5 million more than the previous website.
  • Information is not displayed for living individuals, including submitters.
What this doesn't say is where the information came from. Simply put, it was submitted to The Church of Jesus Christ of Latter-day Saints by members complying with a request to provide their four and five generation family group records. The Research Wiki goes on to explain the limitations of the AF:
The Ancestral File has several key limitations.
  • It contains no notes or sources.
  • Submitters are responsible for the accuracy of the information. FamilySearch did not check the accuracy of any submission.
  • Submitter information, previously available, is now hidden for privacy reasons.
  • Ancestral File contains many errors and corrections are not accepted.
  • Unlike the new FamilySearch Tree and Pedigree Resource File (PRF), Ancestral File is static.
  • As previously mentioned, information in Ancestral File is second-hand. Verify the information before accepting it.
One of the problems with the original website was that these limitations were not obvious nor were they prominently displayed.

Now where is the Ancestral File today? It is incorporated in the search link called "Trees" on the startup page of Here is a screen shot showing the link:

The International Genealogical Index
The IGI contains two types of records, submitted records, like those in the AF, and extracted records. This is explained again in the Research Wiki:

The International Genealogical Index (IGI) is a computer file created by The Church of Jesus Christ of Latter-day Saints. It was first published in 1973 and continued to grow through December 2008. It contains several hundred million entries, each recording one event, such as a birth, baptism (christening), marriage, or death.

Information in the IGI came from two sources:
1.  Some of the entries in the IGI were indexed by the genealogical community from collections of vital and church records. Indexed records are valuable sources of primary information. Unfortunately, attempts to prevent duplication resulted in the exclusion of some indexed records.
2.  Some of the information in the IGI was contributed by members of the Church about their ancestors. The quality of this information varies. Duplicate entries and inconsistent information are common. Always verify contributed entries against sources of primary information.
Both the extracted records and the contributed records are available to be searched on in the Historical Record Collections. A search from the startup page will automatically include the extracted records, but if you want to search both specifically, you need to click on the records listed next to the map on the bottom of the page and search for the International Genealogical Index (typing international will work).  Here is the search screen, showing you the option to search either the contributed or extracted records:

Of course, these records also have limitations as indicated above.

The Pedigree Resource File
This collection of user contributed files was initially promoted as a way to backup data. The files vary greatly in their reliability. Here is the description from the Research Wiki:

Pedigree Resource File (PRF) is a growing collection of user submitted genealogies. It shows individuals’ names; family relationships; and dates and places of birth, marriage, and death. No merges, corrections, or additions are made to genealogies submitted to Pedigree Resource File.
The limitations are also listed:
  • Submitters are responsible for the accuracy of the information. FamilySearch does not check the accuracy of any contributed genealogy.
  • Information in Pedigree Resource File is second-hand. Verify the information before accepting it.
  • Submitter information, previously available, is now hidden for privacy reasons.
  • Pedigree Resource File contains many errors and unlike the new FamilySearch Tree, corrections are not accepted. Submitters are advised to make another submission that includes corrections. However, both old and new submissions are left in Pedigree Resource File.
 Some of the PRF records are searched when you do the same search for the Ancestral File records from the startup page as shown above.

The extracted records in the IGI have the same level of reliability as any other index or extracted records, that is, they may be right or not. The rest of the records are user submitted records and really need to be verified before using.


  1. Thanks for the explanation, James. I liked the "old" IGI and still haven't got my head around the new version. I have access to the original Scottish records here in Edinburgh, so I only use the IGI as a secondary index to extracted records. Any index may have errors, so it's useful to have a second option if I can't find a record in Edinburgh. Jo

  2. James, it is great that you took the time to post this all-in-one-place account of these materials.

    But should they be called "records"? Except for the extracted-from-?records IGI component, they are like user-submitted trees anywhere on the web: asserted conclusions, surmises and/or speculations which might be copied from some publication or just from another family group sheet. Source publications for such genealogical statements might or might not be based on any evidentiary research at all, or might be principally comprised of erroneous assertions (say, Virkus' compilations or The Horn Papers). There is no way to tell what nearly any of it came from.

    In my view, calling it "second hand" rather than "unsupported assertions" is a little deceptive.