[ckan-discuss] Groups -> themes?

[Sean Hammond]

Here's what each is for, as far as I understand (I agree - it would 
probably be useful to have something like this in the user guide):

 > 1. organizations: maximum one per datasets, affects permissions for
> editing and viewing

Are about auth, for controlling who can view, edit, create and publish 
datasets. (I agree that Publishers might have been a better name for this.)

> 2. dataset type: exactly one per dataset, can't be changed after
> creation, affects dataset schema, has separate search page

Are for when you want to have different types of datasets that have 
different schemas. (This is a technical topic, belongs more in the 
Writing extensions docs than in the user guide.)

> 3. groups: anyone on the instance can create, not typically harvested
> with datasets, can store extra information in the group, may have
> multiple group types (similar to tag vocabulary fields)

Are for when you want to group datasets together under a theme e.g. 
climate data etc. You don't want just anyone to be able to add datasets 
to your carefully curated climate group, so only users who are members 
of the group are allowed to add datasets to or remove them from the group.

Unlike with organizations, being a member of a group doesn't give you 
permission to create or edit the datasets in the groups, groups are 
about collecting existing datasets together into groups, they're not 
about publishing datasets.

> 4. tag vocabularies: must be able to edit dataset to change, limited
> selections, cannot store extra information in the tag, associated with
> a particular dataset field (may have multiple vocabularies, similar to
> group types)

These are just for when you want to add a custom field to the dataset 
schema, e.g. "Genre", and you want that field to be a drop-down list 
with a fixed number of possible values. There's an API for adding and 
removing from the list of possible values. Again this is a technical 
topic that belongs more in the extension writing docs than in the user 
guide.

> 5. free-form tags: must be able to edit dataset to change, any
> suitable text, cannot store extra information in the tag, one set of
> tags per dataset

Completely free-form tagging