Finding IOE Books in Explore: Keywords: Home

How to search for LCSH and LET

In UCL Explore both keyword and subject searches will search LCSH and the LCSH tags will be visible in the record.However, LET is only keyword searchable, and the tags are not visible in the record.

In the vast majority of cases the LET and LCSH tags are the same and an appropriate keyword search will retrieve records tagged with either set of tags. However, in a limited number of cases the tags are different and therefore two sets of keywords searches may have to be used.

To conduct a comprehensive search of records tagged with both LET and LCSH, a keyword search should be used in UCL Explore.

In August 2016 the UCL Institute of Education Library (IOE) stopped using in-house tagging using the London Education Thesaurus (LET) for IOE books and switched to using Library of Congress Subject Headings (LCSH), the same tags as other UCL libraries. This means that IOE books in UCL Explore have been tagged with both LET, LCSH, or sometimes both.

This LibGuide lists search strategies you should use to find IOE material tagged with both LET and LCSH.

Which records have which tags

• Ebooks have only ever been tagged using LCSH.
• If there are no copies of a (physical) book at IOE it is tagged with LCSH.
• All books published from 2017 will be tagged using LCSH.
• If a book was published in 2016 or earlier and the only copies are in the IOE Library then it may be tagged with either LCSH or LET or both.
• Though we are now tagging with LCSH the vast majority of IOE books only contain LET tags.

Differences between LET and LCSH

The Keywords tab above alphabetically lists the important subject areas where the tags are different and the tables contain the two sets of keywords required to conduct an exhaustive search which includes IOE material.

In summary:

• The change in tagging only affects books in the IOE Library.
• In most cases the tags are actually still the same.
• Old IOE tags (LET) are now only keyword searchable (i.e. not subject searchable).
• LCSH tags are both keyword searchable and subject searchable.
• This means that keyword searches are required to find material tagged with both LET and LCSH.