Once data has been collected, it has to be checked/edited for consistency and structured for easy access. Datasets should be grouped by topic or theme and described with both tags and brief explanations for users to be able to find. Part of this organization is the use of a taxonomy or classification scheme. Taxonomies guide thinking about the data by establishing broad categories, sub-categories, and members. These categorical relationships between different sets of information can be diagrammed as trees, with category members branching off from categories.
There are 9 top-level categories, which are shown below: