Open data is data that is freely available for anyone to access, use, modify, and share for any purpose. Open data is often labeled with an open license specifying limited restrictions.
The full Open Definition gives precise details as to what this means. To summarize the most important:
Availability and Access: the data must be available as a whole and at no more than a reasonable reproduction cost, preferably by downloading over the internet. The data must also be available in a convenient and modifiable form.
Re-use and Redistribution: the data must be provided under terms that permit re-use and redistribution including the intermixing with other datasets.
Universal Participation: everyone must be able to use, re-use and redistribute - there should be no discrimination against fields of endeavor or against persons or groups. For example, ‘non-commercial’ restrictions that would prevent ‘commercial’ use, or restrictions of use for certain purposes (e.g. only in education), are not allowed.
Why is Open Data Important?
There are many reasons why open data is important:
Replicable - open data sets allow for replication and verification.
Continuity - open data allows researchers to continue research without the added burden of re-gathering data.
Transparency - open data provides transparency to research findings
Validation - open data provides the means to validate published research
Innovation and Economic Value - open data provides new opportunities to understand markets and build new products.
Accountability - open data provides an avenue of accountability to researchers.