Top of page

Endangered Business Data

Share this post:

What is endangered business data? It can probably mean a lot of things, but what comes to my mind first is this: business information and data sets that are inaccessible, nonexistent, or in danger of becoming so.

For example, there could be gaps in coverage, print sets lost, microform copies decomposing or unreadable without proper equipment, or any number of other reasons why business data is inaccessible or nonexistent.

Thomas Register in the stacks

A great illustration is The Thomas Register of American Manufacturers, which is a long series of volumes about manufacturing companies in the United States. (E.g. If you were looking for companies that manufactured furniture in the 1950s, you would look in the Thomas Register.) For this title, the Library of Congress has print editions, microform collections, and provides access to the online database

This one title shows many of the ways business data can be endangered. Here’s how the print collection, microform collection, and electronic access for Thomas Register and ThomasNet are endangered:

Print run of Thomas Register

The Thomas Register of American Manufacturers was printed from 1905-2003. The title changed to Thomas Register in 2004-2006. Total, the series ran from 1905-2006.

The Library catalog record lets you know which years, editions, and volumes, are available from the print run. Here’s how it’s written in the “Older Receipts” section of the record:
1st ed.-63rd ed. (1905/1906-1973), 65th ed.-90th ed. (1975-2000).

The bold red comma tells me that the 64th edition in 1974 is not available. If it were, the range would read like this:
1st ed.-90th ed. (1905-2000).

In any library collection, print books can get lost in a myriad of ways. Sometimes at the Library of Congress, especially for a title like Thomas Register, individual years/editions get misplaced in the shuffle. Because we also have the microform collection, you can still get the information found in the missing print editions. You’d simply use the microform version instead.

Microform collection of Thomas Register

Registered readers can use Thomas Register on microform in the Science & Business Reading Room. This collection fills in the gaps in the print run from 1905-2006.

Microform is generally a stable format, though it is important to handle it carefully for preservation purposes. Also, microform requires special equipment to read the information; without a microform reader, data is inaccessible.

Online database,

The print and microform collections of Thomas Register stop with 2006 and was replaced by The Library’s access to includes current information.

What happened to information from 2007 to present? If it still exists, it is not easily found.

As you can see, the case of Thomas Register and ThomasNet at the Library of Congress illustrates several ways that business data can be endangered. Data is lost when the print book is lost. Data on microform is unreadable unless you have the right equipment. Data for years lost in the coverage gap between print and digital may not even exist anymore or is at least extremely hard to find. Digital data can disappear at the press of a button, even unintentionally.

When you have a sticky business research question needing possibly-endangered data, your friendly business librarian can help you navigate through the maze of resources. Drop us a line through Ask-A-Librarian or visit the Science & Business Reading Room in the Adams Building. And, be aware of how data “are in danger of being deleted, repressed, mishandled, or lost.”

For more information about data preservation and digital content, visit The Signal, the Library of Congress blog about digital preservation and access from LC Labs.

Add a Comment

This blog is governed by the general rules of respectful civil discourse. You are fully responsible for everything that you post. The content of all comments is released into the public domain unless clearly stated otherwise. The Library of Congress does not control the content posted. Nevertheless, the Library of Congress may monitor any user-generated content as it chooses and reserves the right to remove content for any reason whatever, without consent. Gratuitous links to sites are viewed as spam and may result in removed comments. We further reserve the right, in our sole discretion, to remove a user's privilege to post content on the Library site. Read our Comment and Posting Policy.

Required fields are indicated with an * asterisk.