Describe the data so that it is, if necessary, also possible for others to understand what the data are about, .
Data documentation helps you describe, both for yourself and others, what your data is about. Documentation refers to description of research data, i.e. elaborating on what the datasets consist of, how they have been created, and how they can be used. Such descriptive information is referred to as metadata.
The simplest way to document your data is to create a README file and attach it to the data a s a separate file. Important information in the README file are for example:
If the data is to be re-used or published in the future, documentation must always be done carefully.
You can find more information on documentation in Finnish Social Science Data Archive's Data Management Guide and for example in the JYU guide to data documentation.