The Caltech Libraries collect primarily to support current research.  As faculty members change, or change their research foci, the library responds by shifting its resources to support new areas of research.  Just as Caltech is not a comprehensive university, the Library is not a comprehensive collection; nor is it an intentional archival collection.  Nevertheless, last copies are closely scrutinized before deselecting.

Therefore the Caltech Libraries use available space to provide current and/or relevant print materials primarily for current research and curriculum needs.  To meet this goal, the library’s collection is periodically evaluated based on the criteria listed below.

Criteria for consideration:

  1. Usage: Does the item show evidence of recent or frequent use?
  2. Physical condition: Should a damaged item be repaired?  Should it be replaced?
  3. Format: Is the content reliably available on the Web in digital format?
  4. Duplication: Is demand sufficient for multiple copies of the item? 
  5. Edition: Is a newer edition available or already held by the library?
  6. Intrinsic value: Is the item a seminal work in its field?
  7. Research value: Are older materials still valuable for research interests in this field?
  8. Completeness:  Is the item part of an incomplete set or series, or part of a complete set that the library should maintain intact?
  9. Collection level: How vital is the item for current Caltech research and coursework?
  10. Uniqueness: Is the item held only by Caltech?


  1. Deselection decisions are overseen by a subject specialist.
  2. If desired, other librarians and interested faculty may be consulted.
  3. Library staff use standard library statistics and methods (e.g., circulation statistics, evaluation of the item’s physical condition, duplication, uniqueness, etc.) to identify candidates for withdrawal.
  4. Items listed as missing in the Library Catalog for longer than one year will be reviewed for replacement or withdrawal.

December 20, 2017