Curating a set of materials with as broad, amorphous, and contentious a scope as radicalism is not without its difficulties. What is profoundly radical to some will undoubtedly appear tame to others. Radical movements may be deemed radical according to their ideology or their tactics, or both. The very application of the term “radicalism” is itself a political tool that can be applied at times to garner support for purportedly radical measures, or to appeal to a notion of the radical as inherently extremist or irrational, and thereby used to shut down debate. All of this can have a distorting effect on our ability to discern the actual boundaries of what are acceptable opinions within our society, and therefore also the contours of our shared reality.

The SiRO team maintains a broad definition of radicalism, typically preferring to risk what some users may consider irrelevant search results than to exclude resources which may spark new thinking. That broad approach to selection is informed by the needs of our community of users and contributors, and has typically found focus on materials engaged with the radical agendas of liberatory civil rights movements. In the period 2019—2021, SiRO has focused on aggregating resources relating to gender and LGBTQ equity, racial equity, and indigenous movements.

In technical terms, the SiRO team acquires metadata typically via a bulk transfer from the source institution, via public APIs, such as DPLA’s, in negotiation with vendors, or some combination thereof. The metadata is then transformed into a particular standard developed and utilized by ARC members projects, and cataloged in a central index, searchable in these pages.

If you are responsible for, or even know of, a collection we should include, please get in touch at