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White Paper

By Peter Kraker, Maxi Schramm, Christopher Kittel and the Open Knowledge Maps team
With input from our advisory board and the Open Knowledge Maps community

Version: 3.0 (Update December 2019)

Let us know what you think!
We invite you to share your thoughts on our roadmap and services. You can get in touch via email, Twitter, or by creating an issue in this repository.

Table of Content

  1. Motivation
  2. Introduction to Open Knowledge Maps
    2.1 Services
    2.2 Software and infrastructure
    2.3 Community Engagement
    2.4 Openness
    2.5 Sustainability
    2.6 Governance
  3. Open Knowledge Maps as part of an open discovery infrastructure
  4. Workplan
  5. Support us


The open science revolution has dramatically increased the accessibility of scientific knowledge. In 2015, 45% of research articles were published open access, with a clear upward trend (Piwowar et al. 2017). In addition, we see a huge increase in open research data, which will mark the next wave of openly accessible outputs.

Discoverability, however, is falling behind. With two and a half million papers published every year, and tens of thousands of new research projects launched every week, discovery becomes increasingly difficult. Traditional approaches involving search engines providing long, unstructured lists of scientific outputs are not sufficient any more. We can also see this problem reflected in the numbers: a high number of publications remains uncited (between 12% and 82% depending on the discipline, Lariviere et al. 2008). For research data, this is even more pronounced, with up to 85% of datasets never being cited (Peters et al. 2016). And where it gets really gloomy is the transfer to practice. Even in application-oriented disciplines such as medicine, only a minority of results ever gets transferred to practice, and if so, with a considerable delay (Brownson et al. 2006).

These numbers highlight that accessibility does not equal discoverability and reuse of knowledge. There is a discoverability crisis that negatively affects the efficiency and effectiveness of science and its transfer to practice, canceling out many of the positive effects of increased accessibility. In many ways, we cannot cash the cheques written by the open science movement as long as we do not address this issue.

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Introduction to Open Knowledge Maps

The goal of Open Knowledge Maps is to close the gap between accessibility and discoverability of scientific knowledge. We are a charitable non-profit organization dedicated to dramatically increasing the visibility of scientific knowledge for science and society alike. Headquartered in Vienna, Austria, Open Knowledge Maps comprises of an international community including team members, advisors, and partner organizations.

As part of our mission, we operate the largest visual search engine for research in the world. On our website, users can create knowledge maps of research topics in any discipline based on 150 million scientific outputs. Our services enable a diverse set of stakeholders to openly explore, discover, and make use of scientific content. Among our users are researchers, students, librarians, educators, science journalists and practitioners across all disciplines and geographic regions. Open Knowledge Maps increases the visibility of content from a wide variety of stakeholders such as libraries, repositories, funding organisations, and publishers. At the moment Open Knowledge Maps is the only solution in this space that is free and open, and that is usable without prior knowledge.

Open Knowledge Maps was established in 2016, but it has already become a crucial infrastructure for researchers, students and practitioners around the world. In the last 3 years, we have had more than half a million visits on the website, and more than 140,000 maps were created. In addition, we had more than 1,500 participants in our workshops worldwide. At the same time, we have been rapidly growing our platform and coverage to a stable and user-friendly service with high availability. We have also developed an agile organisation, a strong community, as well as professional outreach and training efforts.

Figure 1: Overview of our services

In the future, we want to enable our users to collaboratively edit and discuss the knowledge maps on our platform, thus transforming discovery from a closed individual process to an open and collaborative one. By sharing the results of our discoveries, we can build on top of each other’s knowledge. This process will be aided by our artificial intelligence core and result in a large-scale system of open, interactive and interlinked knowledge maps for every research topic, every field and every discipline. Users will be able to explore the entirety of scientific knowledge within this system. In addition, we will provide the information generated in the OKMaps system back to the open discovery infrastructure, both the knowledge models as well as metadata improved or added by our users. Therefore, Open Knowledge Maps will be the only visual interface that combines machine learning with human curation, providing a truly human-centered service as a result. View here a video of that vision.

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Discovery services

Our approach is to use knowledge maps for discovery. Knowledge maps provide an instant overview of a topic by showing the main areas at a glance with relevant papers and concepts attached to each area (see example map below).

Figure 2: Concept of a knowledge map, using a simplified example for the area of “heart diseases”

Based on this concept, we operate the largest visual search engine for research in the world. On our website, users can create knowledge maps of research topics in any discipline (see Figure 2 for an example). Users can select between two integrations: BASE, the Bielefeld Academic Search Engine, which provides an index of more than 150 million scientific outputs, and PubMed, the large bibliographic database in the natural sciences with a focus on biomedicine. In addition, we operate a service that makes it possible to create knowledge maps of research projects. VIPER, the Visual Project Explorer, enables users to systematically explore a project’s output, and to understand its reception in different areas.

Our search services incorporate a wide variety of in total 21 output types including datasets and multimedia files, and many resources, especially from university repositories, that are not included in commercial search engines. In addition, we do not restrict language in searches, thus increasing the visibility of non-English language content and making the service especially appealing to communities that communicate in a language other than English. We can already see that these efforts have paid off. Open Knowledge Maps serves both users from the Global South and the Global North: most of our page views are from users in Indonesia, followed by the US, India, Germany, Austria, the UK, China, Canada, and Australia. In fact, we are seeing some of the strongest growth in the Global South with countries like India (109,000 page views, a fivefold increase in 2018), South Africa (10.500 views and a threefold increase in 2018), or Nigeria (a fourfold increase to 10,000 page views in 2018).

Figure 3: Knowledge Map of "digital education", online at

Open Knowledge Maps supports a number of use cases, for which no other comprehensive tools existed before. These use cases include getting an overview of a topic at a glance and understanding the terminology related to that topic. Open Knowledge Maps also enables users to easily separate relevant from irrelevant papers with respect to their current information need by clustering papers into subtopics. Such cross-discipline overviews become more and more relevant as the biggest problems of our time (including climate change, migration, globalisation) require an interdisciplinary approach. We also allow for direct access to OA papers within our interface, and offer annotation capabilities for these papers courtesy of Hypothesis. Thus, we enable users to do a large part of their literature research within the same browser tab.

Outside of open infrastructures, the need for systems providing visual overviews of scientific fields has also been identified. At the moment Open Knowledge Maps is the only solution in this space that is free and open, and that is usable without prior knowledge.

Try out our service and let us know what you think.

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Software and infrastructure

Open Knowledge Maps is based on the open source knowledge mapping framework Head Start. Head Start is a high-performance and high-availability software stack that is capable of automatically producing knowledge maps from a variety of data, including text, metadata, and references using unsupervised machine learning techniques.

Head Start includes connectors to a number of academic search engines through rOpenSci, including BASE, PubMed, OpenAIRE, PLOS, and DOAJ. We retrieve the metadata of the most relevant documents for a search term from the respective database, and create a knowledge map in four steps:

  1. Documents are preprocessed by cleaning metadata like title, abstract, author, and journal by removing punctuation, filtering stopwords, transforming to lower-case and stemming.
  2. Similarity of documents is then calculated based on the cosine-similarity of cleaned metadata.
  3. The documents are then clustered into groups with Ward’s method of minimum variance, and placed on the map with non-metric multidimensional scaling.
  4. Finally, clusters are labeled by taking the top three n-grams of keywords, weighted by Term Frequency - Inverse Document Frequency.

In short: the more words two documents have in common in their metadata, the closer they are placed to each other on the map, and the more likely they are assigned to the same area. The representation of the knowledge map is stored in a database from where it is delivered to the user facing frontend. The frontend consists of a web-based interactive visualization, which follows the Shneiderman’s (1996) principle of "Overview first, zoom and filter, then details-on-demand". Knowledge maps are complemented by a synchronized list representation of documents and an integrated PDF viewer and annotation tool courtesy of Hypothesis.

Head Start has a client-server architecture with the user-facing search interface and interactive map frontend based on JavaScript and D3.js. The service and API layer is based on Apache/PHP, and the the natural language processing/machine learning backend is written in R. The architecture is complemented by a persistence and versioning system based on SQLite.

The overall technical design aims to balance two goals: reliability of service and ease of maintenance. We choose underlying technologies according to robustness and versatility rather than novelty or specialization, to focus development efforts on improving the user experience. Through our choice of open source software, which themselves are developed and maintained by large communities, we avoid vendor lock-in effects and long-term dependencies.

The source code for the whole service is available under the open source MIT License on GitHub. In regular frequency we publish new releases of our software, which are available as open source packages and archived via Zenodo.

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Community Engagement

In the past years, we have successfully established a wide array of user engagement activities, including (1) talks and workshops at research institutions, libraries and conferences around the world, as well as via webinars, (2) engagement via our newsletter and on social media, (3) and our Enthusiasts program. These activities are aimed at our diverse stakeholder groups, involving different aspects of the discovery workflow. These aspects include both the reader’s and the author’s point of view (finding and getting found), as well as insights into the functioning of discovery tools and the discovery infrastructure in general.

Our engagement activities are reusable under CC BY, making it easy for our stakeholders to run their own trainings. We provide them with instructions and materials that are also published on our website for self-guided workshops and lectures. Currently, stakeholders can choose between two different formats (“The Scientific Scavenger Hunt” and “Academic SEO”). Both workshops have strong participatory elements. In “The Scientific Scavenger Hunt”, we play a game with the participants that introduces them to Open Knowledge Maps and helps improve their literature search skills along the way. In “Academic SEO”, we discuss the inner workings of search engines and tools that participants use for discovery.

In the Enthusiasts program we involve Open Knowledge Maps power users and ambassadors in our engagement activities. Under our guidance, participants with diverse backgrounds from all around the world conduct workshops on open discovery and Open Knowledge Maps in their communities. In doing so, they collect valuable feedback on the future development of our services. These activities give us a unique opportunity to better understand our user groups and their specific needs, especially in regions and communities that we cannot reach, and thus drive the Open Knowledge Maps development from a community perspective.

Figure 4: Impressions from our training sessions

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Open Knowledge Maps is an open infrastructure based on the principles of open science: source code, content and data are shared under an open license. We are a building block of the open discovery infrastructure, with which we extensively collaborate. As a community-driven initiative, we develop our services in a participatory process together with our stakeholders (see section 2.6 on governance). Our aim is to create an inclusive, sustainable and equitable infrastructure that can be used by anyone, independent of geographic area, age, or stakeholder group. Therefore, we are also conducting workshops to introduce potential users to the tool and help improve their discovery skills along the way. In our community program, the Enthusiasts program, we support power users and ambassadors to conduct workshops themselves and to give feedback from their community’s perspective.

Figure 5: Open Knowledge Maps is an open infrastructure that is community-owned and community-driven

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Our funding model consists of three main pillars:

(1) funded projects
(2) membership-based funding
(3) donations

Of these, funded projects currently provide the largest income. In this pillar, we create new discovery services using our open source software. The outcome must always serve the public good. These projects are either funded by a collaborating institution (e.g. Ludwig Boltzmann Gesellschaft or Austrian Academy of Sciences) or by a 3rd party funding body (e.g. the European Commission or Mozilla)

Funded projects currently cover only a small percentage of our activities - the largest part is donated in-kind as volunteer efforts. So far, we achieved EUR 100,000 in funding, which partially covers the activities of the core team. In addition, project-based funding is highly volatile. To achieve financial, technical, and organisational sustainability we will complement funded projects with membership-based funding. In our membership-based funding model, supporting organisations become members of Open Knowledge Maps and provide an annual contribution. In return, members get a say in the future development of Open Knowledge Maps. Members are invited to join the Board of Supporters, which participates in a yearly vote on what features and sources to implement. This establishes a true community-driven solution for the discovery of scientific knowledge.

Donations are our third pillar, and our smallest yet. In November/December 2018, we launched our first donation campaign. The feedback from the community and the results were encouraging. With the funds raised, we will be able to cover our server costs for 2019.

We know that increased openness does not automatically lead to a more equitable world. It needs organizations and services that translate this openness in a way that everyone can benefit from it. Open Knowledge Maps is in a prime position to do so having developed a service and interface that can be understood across geographical borders, age groups and societal stakeholders. At this moment we need more funding to do that in a sustainable way.

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Open Knowledge Maps’ structure is largely determined by the legal requirements for a charitable non-profit (“gemeinnütziger Verein”) under Austrian law (Vereinsgesetz 2002) and defined in the organization’s bylaws.

Open Knowledge Maps has the following branches (see Figure 2 below):
(1) The executive branch, which consists of the Executive Board and the team
(2) The advisory councils, including the Advisory Board and the Board of Supporters
(3) The monitoring facilities, including the arbitration tribunal and the auditors
(4) The community, with our users (including the enthusiasts), partners, and networks.

Figure 6: The Open Knowledge Maps governance structure

The Executive Board is responsible for the management of the organization and the team. Together with the Executive Board, the team carries out the work to realize the purpose of the organization.

The Executive Board has two advisory councils: the Advisory Board and the Board of Supporters. The members of the advisory board advise the Executive Board on organisational and technical development and the means for achieving the purpose of the organisation. The Advisory Board is designed to represent the diversity of stakeholders of the organisation, including users, partners, advocates and so on. Advisors are appointed for one year by the Executive Board; the appointment can be renewed.

The Board of Supporters consists of the supporting members. Depending on the extent of the membership fee, a supporting member can appoint up to three representatives to the Board of Supporters. The Board of Supporters gives input to the technical roadmap and is involved in the decision making process regarding the technical roadmap in a yearly voting. The vote of the Board of Supporters is weighted 1/3 towards the composition of the final roadmap. The other two thirds are decided by the wider Open Knowledge Maps community in a community voting (weighting: 1/3) and a voting by the Open Knowledge Maps team and executive board (weighting: 1/3).

The auditors are responsible for auditing the financial management of the association with regard to the regularity of accounting and the use of funds in accordance with the bylaws of the organization. For the arbitration of all disputes arising within the association, the arbitration tribunal of the association is called. It is a "mediation facility" according to Austrian law (Vereinsgesetz 2002).

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Open Knowledge Maps as part of an open discovery infrastructure

Discovery is a space that has traditionally been dominated by commercial players (Elsevier, Clarivate, Google), and with more resources becoming available thanks to Open Science, they have recently increased their activity in this area. In the past two years alone, we have seen the market entrance of Springer with Digital Science Dimensions, as well as the launch of Google Dataset Search and Elsevier DataSearch Beta 2.

Commercial infrastructures have, however, demonstrated a stronger emphasis on reaching market dominance than on developing innovative services. Their reliance on proprietary indices and list-based interfaces, and a lack of community-driven development has led to the current discoverability crisis (see also section 1). In addition, commercial infrastructures retain all governance over their systems, including user data and algorithms, and due to their proprietary nature lead to lock-in effects. Thankfully, we can see an open discovery ecosystem emerging (see Figure 3). But this system is still developing: in a recent analysis Bianca Kramer and Jeroen Bosman identified just three scholarly commons-compliant infrastructures in the area of discovery - Open Knowledge Maps being one of them.

Figure 7: The open discovery infrastructure

The open discovery system is still fragmented and it needs innovative, cross-disciplinary frontends and infrastructures that act as a catalyst for its development. Open Knowledge Maps does not seek to replace traditional search engines, but to complement their strengths. While search engines help users whose information need is clearly defined to access research outputs, Open Knowledge Maps provides discovery services that put single pieces of research into context, giving users with a more fuzzy information need multiple entry points into a topic. We also see ourselves complementary to the efforts of visualization tools such as VOSViewer or Scholia, which require expertise in creating and manipulating datasets. We therefore seek to create a useful workflow between all of these systems (see our collaborations with BASE, OpenAIRE and Scholia).

We believe that we have what it takes to act as a catalyst for this infrastructure. Due to our broad use, we have the ability to increase the visibility of features and services developed by the rest of the open discovery infrastructure. Open Knowledge Maps already acts as a catalyst for source applications in BASE. We also collaborate with rOpenSci, who develop all of our data clients. These clients are then also available as standalone R packages. Thus, when Open Knowledge Maps grows, the data science community also benefits. We have also already integrated Hypothesis, and we are planning integrations of other services. We believe that in this way, we can best use the advantages of openness and jointly become a viable alternative to the proprietary infrastructure.

We also provide a well-tested, user-facing open source service, thus bringing an innovative reusable interface to the open infrastructure. This is of huge value to our stakeholders, which can use our interface to provide better discoverability for their collections. This is exemplified by collaboration projects with the Austrian Academy of Sciences and the Ludwig Boltzmann Gesellschaft, an OpenAIRE tender project, and an upcoming EU project with OPERAS.

In addition, we are strong advocates for the open discovery infrastructure. In the #DontLeaveItToGoogle campaign, we spread awareness for the need for an open discovery ecosystem and open infrastructures in general using tweets, blog posts, and invited talks. (See these blog posts for an overview of activities: #DontLeaveItToGoogle Campaign and Update on the DontLeaveItToGoogle Campaign) This has been met with a lot of interest: we have now reached about 100,000 people with this campaign, and already received invitations for follow-up pieces and talks.

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Our work plan has three main pillars:
(1) maintaining and developing our core services
(2) carrying our community and training activities
(3) implementing our funding model.

It is structured along 9 crucial objectives. Note that we do not include a timeline for the work plan at this point, as its implementation strongly depends on the available funding. Currently, we are looking for dedicated funding for all activities, as well as expressions of interest from organizations to become supporting members.

1) Achieve financial sustainability
We are looking to achieve financial sustainability by strongly developing the sustainable pillars of our funding model, in particular the membership-based funding model. In addition, we will continue our donation program. We do have an existing setup that allows us to run a donation campaign with minimum effort. We will therefore keep doing this to gather more insight into how we can grow this instrument. We will still look to acquire project-based funding that has a strong alignment with our overall roadmap, but to a lesser extent.

2) Strengthen integration with the non-profit open science infrastructure
If we want to be taken seriously as an alternative to proprietary infrastructures, the open infrastructures need to work together towards a better user experience. To this end we will work on a more seamless integration of complementary functionalities of other services into our own service. This will in turn provide backlinks to the rest of the infrastructure and increase the use of their services.

Based on user feedback and popular use cases we are planning to e.g. integrate following functionalities within the next two years:

  • DOAJ: include the Seal of Approval
  • ORCiD: include ORCiDs from BASE and link to them
  • unpaywall: provide links to additional open access copies
  • OA Button: provide OA Button within the interface for non-OA items
  • Zotero: enable exporting citations to Zotero

We will also perform user tests evaluating the implementation of the functionalities mentioned above. In addition, we will work towards integration of our functionalities in other open infrastructures.

3) Provide data interfaces to our database
The open science ecosystem relies on the creation of positive network effects, from which we benefit in our daily use of open APIs, and to which we want to contribute by offering an API to our own services and data sets. This includes providing a means of access to our services’ knowledge mapping capabilities (‘Discovery as a Service’), and bulk data access to our underlying data sets, so that other initiatives can re-use this for e.g. building on top of that data or research purposes. For those sections of our future data sets that include user-contributed content, our data interfaces will be constrained to data for which users consciously opt-in prior to any publication.

4) Improve our capabilities for data discovery
Research data are among the fastest growing openly accessible scientific outputs. There is a need to improve on the low rate of discoverability to increase the reuse of FAIR data - up to 85% of datasets are never cited (Peters et al. 2016). Moreover, several new entrants to the data discovery market are following a closed and proprietary model, therefore creating open alternatives becomes all the more important. We want to transfer our accumulated experience and competences from literature discoverability to visibility and discoverability of research data across disciplines. We are building on our existing experiences with including data sets in knowledge maps as part of the VIPER project, and supplementary datasets included in BASE. Our role as lead in the GO FAIR Implementation Network “Discovery” puts us in a unique position to work with the community on three tasks:

  • Stocktaking: We will identify relevant open indices and innovative open source interfaces and user-facing services to be (re-)used, as well as the main use cases that we want to address.
  • Structuring: We will define the standards and structure of an open ecosystem of services and interfaces for data discovery that fulfils the identified use cases.
  • Implementation: We will work towards implementation of the ecosystem laid out above.

5) Refactoring project: improving our platform and its reusability
We will perform fundamental refactoring, which is a necessary foundation for our goal of a collaborative discovery environment. This includes:
(1) A rewrite and extension of the web-based visualization in a reactive framework that allows easier maintenance and addition of functionalities.
(2) The development of a scalable data storage architecture that better enables future growth, introduces data replicability and further reduces risk of data loss via an improved backup system.
(3) A rewrite of the backend in a scalable, easy deployable architecture to improve portability across collections and further reduce risks of downtime.

As a direct effect of this, our software can be more easily reused or adapted, and therefore become a standard software package for making collections visible and discoverable.

6) Further develop our community activities, in particular our Enthusiasts program
In the past years, we have successfully established a wide array of community activities, including workshops, webinars and our enthusiasts program. These activities give us a unique opportunity to better understand our user groups and their specific needs, especially in regions and communities that we cannot regularly interact with, and thus drive the Open Knowledge Maps development from a community perspective. Apart from a science mini-grant from Mozilla and the Sloan Foundation, these activities were created entirely on volunteer time. Moving forward we want to maintain existing activities and we will work towards expanding the program by involving curriculum managers to reach a bigger audience. We also plan to stepwise increase the number of participants that we take on the Enthusiasts program (currently 6), to develop new and improved materials and to support enthusiasts financially when conducting bigger events.

7) Continue our communication and support efforts and make them sustainable
We have already established professional communication and support via our website, newsletter and social media channels. As with the community efforts, these are completely volunteer-based at the moment. Over the next two years, we will make our communication efforts sustainable so that they can be carried out by any person within the organisation. This includes a written social media strategy that lays out our coordinated activities across our social media channels to be able to use these more effectively and increase followers and attract new users. On our website, we are planning to replace our news and community sections with a CMS. We will also dedicate a new page to our governance structure and decision-making processes. In addition, we will continue to update the content on our website regularly and send out a newsletter every 4-6 weeks.

8) Continue our advocacy for and networking with open infrastructures
We have started a very successful advocacy campaign for open infrastructures, which has already reached about 100,000 people. We will continue working on this campaign with posts, interviews (including one with Open Science Radio), talks and via social media. We will also continue our work in leading open science and open infrastructure networks, including JROST, GO FAIR, the Leibniz Research Alliance Open Science, AAKC, OANA (Open Science Network Austria) and CSNA (Citizen Science Network Austria).

9) Prepare the organisational transition to paid staff and improve operational transparency
We have already successfully transitioned from a pure volunteer organisation to one that mixes volunteer work with funded projects. We have set up an organisational structure including executive and administrative functions, supported by a number of project management tools, that allows us to do that in an agile way. Going forward, we will establish the necessary processes and administrative functions to deal with paid staff.

Going forward, we will improve our operational transparency. We already provide information about our sustainability goals and efforts on funding, including our membership-based funding model and will continue to do so. We will also communicate our governance structure and decision-making processes on our website.

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Support us

You can support Open Knowledge Maps in a variety of ways:

Let us know what you think: share your thoughts on our roadmap and services via email, Twitter, or by creating an issue in this repository.

Become an enthusiast: are you interested in spreading the word on open discovery and Open Knowledge Maps? Sign up for our Enthusiasts program

Make a donation (for individuals and organizations): If you want to help us financially in achieving our goals, consider making a donation.

Become a supporting member (for organizations): to provide a sustainable platform for open discovery, we propose to fund Open Knowledge Maps in a collective effort: organizations become supporting members and provide a yearly contribution. In return, our supporting members are invited to co-create the platform with us. Find out more on our website.

Fund our roadmap (for funders): we are currently looking for dedicated funding for all activities in our work plan. Please get in touch with Open Knowledge Maps founder and chairman Peter Kraker.

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