TRLN Discovery Subject Re-Mapping Program

Whether expecting it or surprised to experience it, users encounter metadata in library systems that offend, exclude, and dehumanize people. The complexities of how metadata displays alongside a particular resource is not easily conveyed as users conduct their research without disrupting their experience. Rectifying the use of these metadata, such as outdated Library of Congress subject headings in library systems, takes time and resources libraries may not have, but with modern practices and more flexible technology comes new opportunities for libraries to create a more inclusive search experience.

Technical Solution

The TRLN Discovery development team created an elegant solution to overlay or remap subject headings identified as problematic by users with preferred terms. They created a simple configuration file to capture the problematic term and the preferred term being mapped to it. When a new term is added to this file, each institution re-processes their records using the subject heading to make the change visible to end users. Some examples of terms currently overlaid include “Illegal aliens” (overlaid with “Undocumented immigrants”), “Slaves” (overlaid with “Enslaved persons”), and “Dirty War, 1976-1983” (overlaid with “Terrorismo de Estado, Argentina, 1976-1983”).
Access the full list of overlaid terms.

Remapping a subject heading does not change the MARC record data or search results. It instead changes subject data that displays to the end user. Additionally, remapped headings must be specified at the whole subdivision level. This requires some repetition in the configuration file, but this also accommodates nuance in the remappings. If a user searches for “illegal aliens”, they will return results using this term; however the subject facet and the item record’s subject will display “Undocumented immigrants”. The remapping only applies to subject headings. If “Illegal aliens” displays elsewhere, such as title, then this information will not be overlaid with “Undocumented immigrants”. The change is subtle for end users in the Blacklight discovery layer, but we think this makes a significant impact in creating a more inclusive and representative search experience for users.

About the Process

The technical mechanism to overlay problematic subject headings is somewhat simple. The process to review and decide whether a term is within scope of the program is more complicated.

Users can submit suggested terms to overlay using this form. The TRLN Discovery Metadata Team reviews, researches, and documents decisions made for each suggested term. Some terms have been extensively discussed in broader communities and we can point to this work when making our recommendations. Some suggestions may require collaboration with the TRLN Metadata Interest Group, subject matter experts, and other stakeholders to determine whether a term should be remapped as part of this program and what is the preferred term. Ultimately, the TRLN Discovery product owners review the recommended terms to remap and if they approve, the terms are added to the configuration file and visible to end users. We believe this multi-step decision and approval process opens up additional feedback channels to multiple stakeholders and attempts to make this process more transparent, while the team continues to iterate.

Suggest a Subject Heading

Have a problematic subject heading to suggest for remapping? Use this form and the TRLN Discovery Metadata Team will review and follow up with your suggestion. For questions about this program, contact

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