Anything that can be used for analysis can be considered "data(sets)". Many national and international organisations provide access to large datasets free of charge: this is called Open Data.
These datasets may contain different kinds of data files, e.g. raw or edited/cleaned data, and macro or micro data. Raw data refers to the data as it is primary collected, and includes all data, even the missed or mismatched pieces in the data file. Edited or cleaned data refers to the data file as it has been used by the researcher for analysis and publication. Macro data and statistics are results based on micro data units, which provide a general overview of the micro data. Although these datasets are very different in kind, they all contain very important information.
When reusing research data, scientists must be familiar with the rules and regulations governing data copyright, intellectual property rights, and participant consent for the reuse of data and personal information. SURF has compiled a report on the legal status of raw data including information on the types of consent required for the reuse of data.
See also the ZonMw explanation of different kinds of property rights in the Netherlands (text available in Dutch only).
The number of datasets that are available on the internet grows rapidly. In some cases a license or subscription may be required to use them. The library of the Vrije Universiteit Amsterdam has collected links to some of the most often used data repositories and has licensed several databases.
If you need help finding & using free or licensed sources you can contact the Research Data Services Helpdesk. For students and personnel in the fields of economics, finance, or organisation science a separate LibGuide has been created to help them find and use/re-use data.
You can also start looking for data in these four places:
Data portals of (governmental) organisations. Organisations that regularly collect (statistical) data sometimes offer this data through their own portal. An example is Eurostat, which collects and disseminates statistics at the European level, by country and by theme. Some of these websites have been linked in the Finding data LibGuide.
Researchers from the Vrije Universiteit Amsterdam have also developed some databases containing data collected during research. See here some examples:
NARCIS is dé nationale portal voor wie informatie zoekt over wetenschappers en hun werk. Naast wetenschappers maken ook studenten, journalisten en medewerkers binnen onderwijs, overheid en het bedrijfsleven gebruik van NARCIS.
NARCIS biedt toegang tot wetenschappelijke informatie waaronder (open access) publicaties afkomstig uit de repositories van alle Nederlandse universiteiten, KNAW, NWO en diverse wetenschappelijke instellingen, datasets van een aantal data-archieven, alsmede beschrijvingen van onderzoeksprojecten, onderzoekers en onderzoeksinstituten.
Dit houdt in dat NARCIS (nog) niet gebruikt kan worden als ingang tot complete overzichten van publicaties van onderzoekers. Er zijn echter steeds meer instellingen die al hun wetenschappelijke publicaties via NARCIS toegankelijk maken. Op deze wijze kunnen de publicatielijsten van de wetenschappers zo compleet mogelijk worden gemaakt.
In 2004 is de ontwikkeling van NARCIS gestart als een samenwerkingsproject van KNAW Onderzoek Informatie, NWO, VSNU en METIS in het kader van de dienstenontwikkeling binnen het DARE-programma van SURFfoundation. Dit project heeft de portal NARCIS verwezenlijkt, waarin in januari 2007 de dienst DAREnet is geïncorporeerd. Sinds 2011 is NARCIS een dienst van DANS.
National Academic Research and Collaborations Information System
NARCIS is the main national portal for those looking for information about researchers and their work. Besides researchers, NARCIS is also used by students, journalists and people working in educational and government institutions as well as the business sector.
NARCIS provides access to scientific information, including (open access) publications from the repositories of all the Dutch universities, KNAW, NWO and a number of research institutes, datasets from some data archives as well as descriptions of research projects, researchers and research institutes.
This means that NARCIS cannot be used as an entry point to access complete overviews of publications of researchers (yet). However, there are more institutions that make all their scientific publications accessible via NARCIS. By doing so, it will become possible to create much more complete publication lists of researchers.
In 2004, the development of NARCIS started as a cooperation project of KNAW Research Information, NWO, VSNU and METIS, as part of the development of services within the DARE programme of SURFfoundation. This project resulted in the NARCIS portal, in which the DAREnet service was incorporated in January 2007. NARCIS has been part of DANS since 2011.