I recently added a couple of pages to the Resource section of my web site, providing IGI Batch numbers for various locations in Germany and the United States. For those not familiar with the International Genealogical Index (IGI), it is an index to microfilm records found in the FamilySearch library. When volunteers indexed a record set found on a film, the results were assigned a batch number. By restricting a search of FamilySearch to a given Batch number, the search is limited to the records from the given locale. This allows more precision in the search and reduces the number of unrelated results.
This reminded me of how I used the advanced search capability of IGI to find my great grandmother’s family. This was done years ago on the computer at my local Family History Center, before the capability was available on the Internet. The facts I knew was Michael Velten had married Catherine Miller in Ohio. Should be simple, but a quick check of a printed census index showed there were at least 300 Catherine Millers. There was no Ancestry and no Internet, so manually viewing each entry required cranking through microfilm at the NARA archives in Waltham, Massachusetts.