ADS Digital Library

The ADS Digital Library is a project within the Astrophysics Data System (ADS)- a NASA funded collection of astronomy, astrophysics and physics documents. The ADS collection consists of over 5.6 million records, and primarily holds bibliographic records and full-page scans of astronomical literature. Specifically, within the Digital Library there are full scans of 16 books, which vary in format (some PDF downloadable files, some clickable image links, etc.).

1) Selection Decisions

The reasons behind selecting the 16 books are not made clear on the website. There are two old books included in the collection, and it is implied that they were included due to historical relevance (as they are from their "Historical Literature Collection"). These 16 books are the only full books in the database (the other records are articles and abstracts), but the significance of these texts is not apparent. The books cover varied astronomy topics, and appear to be mostly "foundation" and "fundamental" type texts. The books may be significant handbooks in the astronomy field, but this is not explicitly detailed.

2) Metadata

Each of the 16 books are listed on the home page, along with a bibliographic reference line- including author/editor, publisher, and year of publication when available. After clicking on the book title, you receive further information about the item, such as copyright information, number of pages, and who provided the digital copy. Also, on some items a brief description of the book or project is included. The metadata provides a satisfactory amount of information, and includes reference data if further research is desired.

3) Object Characteristics

By clicking on an item you are given the option to search the book's table of contents. To view individual pages you can select either a chapter or a range of pages. The scanned pages are either in a pdf format that automatically downloads to your computer, or a clickable link that leads you to a scan located on the internet. Unfortunately, there is no way to tell which is going to occur when you click on the link. The books that are linked on the internet are much easier to maneuver. You can click on a page to go directly to it, or you can start at the beginning and click "next page" to go through the pages in order. There is also a very handy printing tool at the bottom of each page that allows you print a page individually or a range of pages. The bibliographic reference information is also at the top of each of these pages. If all the books were in this format, the site would be much more accessible.

4) Intended Audience

The intended audience for this digital library seems to be researchers who are looking for access to particular astronomy texts. The information is printable and searchable, allowing for researchers to pull information and use it in their work. The metadata provided is detailed enough for researchers, and the scans are a high enough quality to print and use as a regular text.