The National Open Data Conference NODC2021 was held in hybrid mode from September 20th to 22nd, 2021. at the Faculty of Transport and Traffic Sciences, University of Zagreb, ZUK Borongaj. As a task from our TODO project (857592), the main goal of the NODC2021 was to disseminate and communicate the project's ongoing results and achievements with the audience – specifically other stakeholders from the field of open data in the Republic of Croatia.

Over 100 participants (both online and in-person) attended the Conference, and over 25 extended abstracts from the fields of law, agronomy, geodesy, informatics and organization, computing, transport, and traffic were presented. Conceived as a three-day event, the NODC2021 was divided into three main sections: keynote speeches, six dedicated discussion panels and two workshops.

Keynote speakers, selected according to their knowledge and experience were prof. Janssen (TU Delft, Netherlands) who presented smart open data with the evolution of open data and the importance of the "smartness" of data. Božo Zeba (Central State Office for Digital Society) presented the review of open data ecosystem developments in Croatia – present state of open data and Aleš Veršič (Ministry of Public Administration, Slovenia) showed the development of open data in Slovenia. Since the TODO project is an interdisciplinary project with partners from different research areas (law, agronomy, geodesy, informatics and organization, computing, transport and traffic), Organizational Committee decided that several panels covering all partners' areas are defined and panel discussions were:

• Data based innovation in the sustainability of natural resources and efficient food production (moderators: Dragica Šalamon, AGRI; Martina Tomičić Furjan, FOI),
• Technological enablers of open data (and beyond) (moderator: Igor Čavrak, FER),
• Open data for citizens' rights and good governance (moderator: Anamarija Musa, LAW),
• Smart industry and digital transformation through data sharing (moderator: Neven Vrček, FOI),
• Open Geo-spatial Data Driver of Modern Society (moderator: Željko Bačić, GEOD),
• Open Data in Smart Cities (moderator: Miroslav Vujić, TRANS).

The first workshop, "Open data for beginners" (Ivana Bosnić, Faculty of Electrical Engineering and Computing) provided an introduction to basic open data vocabulary and examples, showed the need for various categories of open data, explored open data principles, discussed the quality of available open datasets, introduced the basic steps to creating an open dataset, emphasized the importance of metadata and legal issues. Finally, it provided a way to discuss personal levels of agreement for some statements related to open data.

The second workshop, "Show me the data! (Open data mapping)" (Ana Kuveždić Divjak, Faculty of Geodesy), provided a hands-on experience on finding, evaluating, cleaning, combining, and visualizing the available open datasets from various sources, using the open-source mapping tools. Various formats of open datasets and many potential issues were also raised and discussed. As a final result, a map of Zagreb neighborhoods with kindergartens was created and visualized, extended by the population density of each area.

Link to Book of abstracts of the National Open Data Conference - NODC2021