ITHAKA Invests in Open Access Annotation Service Hypothesis

Higher ed nonprofit ITHAKA announced on August 18 that it has invested $2.5 million in Hypothesis, an open annotation service. Hypothesis, developed with funding from the Sloan, Mellon, and other foundations, enables users to make searchable annotations on text across all platforms and interfaces, at a private or public level—from notes and comments to corrections and addenda. And parent corporation Annotation Unlimited (Anno) envisions a time when this capability will be built into all browsers as a native feature, much like search engines.

Ithaka and Hypothesis logosHigher ed nonprofit ITHAKA announced on August 18 that it has invested $2.5 million in Hypothesis, an open annotation service. Hypothesis, developed with funding from the Sloan, Mellon, and other foundations, enables users to make searchable annotations on text across all platforms and interfaces, at a private or public level—from notes and comments to corrections and addenda. And parent corporation Annotation Unlimited (Anno) envisions a time when this capability will be built into all browsers as a native feature, much like search or tabs.

“The shared vision is that conversations will be able to happen anywhere on the web, or even on documents in native apps, and inline instead of below the fold, in a federated, standards-based way,” according to the Hypothesis website. Annotations made via Hypothesis live independently from the native app on which they’re made, and are under the control of the user, rather than the material’s publisher. This allows users to take private or public notes, share information, amend errors, take part in classroom discussions, join global conversations, and more.

Hypothesis is available as a free browser extension as well as a fee-based enterprise service integrating annotation functionality directly into academic learning management systems. It is currently used by more than a million people worldwide who have made nearly 40 million annotations. More than 200 colleges and universities use the service, as well as public and private high schools. As of January, Hypothesis has met all Web Content Accessibility Guidelines necessary for it to be globally incorporated into learning management systems.

Hypothesis will join forces with ITHAKA’s digital library JSTOR, which serves more than 13,000 educational institutions around the world, from K–12 through higher education, providing access to more than 12 million journal articles, books, images, and primary sources. A pilot rollout is taking place this fall at several schools, including Cornell University, Ithaca, NY; Colgate University, Hamilton, NY; Wake Forest University, Winston-Salem, NC; and Las Positas Community College, Dublin, CA. JSTOR and Hypothesis will be available within the learning management systems for teachers to assign.

At the end of the pilot period, Anno’s success team will conduct surveys and interviews with instructors and students to find out what’s working and how it can be improved. This data will also help make the case for Hypothesis’s value to stakeholders, including faculty, publishers, and libraries.



The Hypothesis Project was launched by coder and entrepreneur Dan Whaley in 2011 as a nonprofit organization dedicated to the mission of open, interoperable annotation capability. For more than a decade, Hypothesis has been working to develop its vision for web annotation and build the open-source framework to support it.

Whaley, now chairman and CEO of Anno, sees the idea of open annotation as an extension of the original Open Web Platform technologies that edged out proprietary online service providers to power today’s web. With Hypothesis, communities of users will be able to annotate any internet-connected document, whether in HTML, PDF, EPUB, or other formats. “Google Docs allows you a way to annotate docs stored there, but that system doesn't work over the pages of a book in the Amazon Kindle,” he said “The two platforms are both proprietary and incompatible. We all know this intuitively and kind of just accept it, but it doesn't need to be this way. You get tremendous increases in utility when systems actually interoperate.”

Hypothesis works much as a browser does, detached from any individual application. It allows a user to move seamlessly between layers of annotation experiences, from personal note taking to collaborative groups to larger communities. Annotations are searchable, either privately or publicly, and users can apply their own tags to help organize their notes.

The idea has been around for a long time, Whaley noted; Marc Andreessen built annotation capability into an early version of his Mosaic browser; it was later discontinued as too complex to support. “What if we had a fundamental open protocol for doing this, that the folks that run closed platforms were increasingly forced to adopt?” he wondered. “That’s essentially what happened with services like AOL when the web was created. Eventually all those online service providers had to provide a gateway to the web—otherwise they were going to be left behind, because it was the obvious thing that everybody wanted.”

Whaley and the Hypothesis Project felt it was time to bring the concept of open annotation back. The team helped form and lead the W3C [World Wide Web Consortium, the standards body for the web] Web Annotation Working Group, which spent four years developing a vocabulary, data model, protocol, and formal recommendation for the service that would become Hypothesis. In February 2017, W3C standardized open annotation through the Recommendation for Web Annotation, and the project team began developing its implementation.

In 2019 the Hypothesis Project joined forces with several other organizations, including the Scholarly Publishing and Academic Resources Coalition (SPARC) and the Open Research Funders Group, to form the Invest In Open (IOI) Infrastructure initiative. Under the leadership of Executive Director Kaitlyn Thaney, IOI pursued funding for the project. Anno, launched in August, is funded by a $14 million seed round that included ITHAKA’s investment, as well as funding from, Triage Ventures, Esther Dyson, Mark Pincus, and others.

Anno will concentrate on bringing Hypothesis to the education and research markets, while the Hypothesis Project will continue to focus on advocacy, standards, and further development of the open annotation paradigm.



The collaboration has a great deal of potential on both sides.

ITHAKA is always looking for new ways to use its resources, including its capital reserves, to advance its mission to expand access to information knowledge, noted Alex Humphreys, vice president of ITHAKA Ventures and JSTOR Labs. “One of the things that we’re most interested in is creating open, scalable, sustainable infrastructure,” he told LJ. With the momentum Hypothesis has been gathering in the teaching and learning sphere, he said, investment in the project made sense.

“There’s a lot of negative pressure, as a platform provider, to invent your own everything in order to keep people within a walled garden,” Humphreys noted. “I don’t think that’s sustainable, and I think that creates opportunities for players that don’t share our values to swoop in. So the infrastructure for annotation is something that I’m really excited to be able to support, and we hope it can traverse across platforms, including JSTOR.”

Teachers currently use JSTOR materials, he added, but that usage is often hidden from ITHAKA if instructors download PDFs from JSTOR and upload them into the learning management system—which is actually against JSTOR’s terms and conditions.  Annotations made using the Hypothesis integration, however, will let JSTOR and its content publishers gather content to access data for this increased engagement, capturing usage and impact that has previously gone unreported.

“What we provide is a way to introduce this new interoperable annotation standard as a growing mesh over the world’s knowledge,” Whaley explained. “That means it’s fundamentally rooted in being associated and coming into contact with high quality pools of content, and JSTOR and ARTSTOR represent these really large resources in the scholarly community for archival material that millions of people use on a daily basis.”

ARTSTOR offers access to more than 2.5 million images in the arts, architecture, humanities, and sciences; Hypothesis is currently working on image annotation capabilities, leveraging standards developed by the International Image Interoperability Framework (IIIF) community.

Opening up the web to annotation has a wealth of applications for any given type of document, noted Humphreys, but in partnership with ITHAKA, Anno is concentrating on classroom uses. “The specific use case that they’re seeing a lot of traction with is annotation within a classroom, which aligns with the benefits of close reading and alternatives to just discussion boards,” said Humphreys. “One of the key skills that students need to develop is how to read academic literature. This is not something that you just naturally fall into—that stuff can be a little impenetrable. So that close reading provides a support for that development that is really important.”

For students using textbooks in class, the real-time group annotation tool means “you can raise your hand on any sentence at any time and get help,” said Whaley. Outside the classroom, “research is about collaboration with either your team, or your peers, or your colleagues near and far. Being able to do that basic kind of open post-publication peer review—also in terms of annotation communities, journal clubs, and lots of different kinds of social constructs—we think is one of the things that might help accelerate the metabolism of scholarly discovery.”

Hypothesis has the potential to change not only how content is consumed, but how it is created, added Whaley. “If scholars at the preprint stage, for instance, are making new material and are receptive,” he said, “that can help them improve the work that they’re doing. There will be probably a bunch of different kind of collaborative layers as opposed to just one commentary layer on the back end.”

It may also help increase usage of library materials on campus. “Hypothesis has relationships with teaching and learning centers at universities and colleges. JSTOR primarily has relationships with libraries,” said Humphreys. “Many libraries want their material widely used but are not deeply embedded within the teaching and learning enterprise. If we really want to scale and increase the impact and the value of our collections and our licenses, it’s going to be about breaking down those barriers, or finding ways to bridge them. Open infrastructure is a way that we’re all aligned.”

In the short term, the partnership will allow Anno to build out Hypothesis, test a range of use case scenarios, and get real-life usage data and feedback toward an ambitious, potentially game-changing service.

“For us, it’s a dream opportunity to use this kind of partnership as a test tube in terms of how best to bring utility, through collaboration and conversation and so forth, to one of the world’s leading content sources,” said Whaley. “If we’re successful, this will be an ecosystem—of providers, of platforms, of software implementations that work together. It’s not going to be something that we bring forward, and then it’s just us, and we’re the only ones doing it. This is hopefully a groundswell that leads to something transformative.”

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Lisa Peet

Lisa Peet is Executive Editor for Library Journal.

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