Why are indexes and abstracts so useful?

1. Indexes allow for specificity without being too narrow. Searches can be limited to certain authors, subjects, or even forms (i.e. academic journals, dissertations, essays, etc.)

2. Using indexes and abstracts also saves time by weeding out large amounts of unrelated sources.

3. Older information is more likely to be found, since indexes and abstracts had been around for many decades prior to the internet.

4. Some indexes (i.e. citation indexes) allow for cross-referencing between items. This can lead to a chain of relevant sources, stemming from the first that was found.

5. Indexes and abstracts in their electronic forms support the idea of libraries without walls. A citation can be found in a local index, but the article may then be accessed electronically from another source altogether.

6. Both indexes and abstracts are generally reliable, because they are created by humans for humans. They tend to use human language and controlled vocabulary.*

*A Caveat: This final reason is also why extra scrutiny must be paid. The accuracy falls prey to human error (as many abstracts are written by the authors of the articles) and a controlled vocabulary used for one index may not be at all similar to that of another. Since indexing is done by people as well, it is a costly (and timely) process; therefore, accessibility to indexes is often dependent on the budget of the reference service.