What is a Significant Event?

As the world is in a state of constant change, Who's On First (WOF) records are constantly changing, too. With most record changes, a simple property update and update to thewof:lastmodified property field is sufficient. However, if a Significant Event takes place, additional work is needed.

So, what exactly is a Significant Event and how is it defined?

• Changing a point feature's location more than 10km
• Changing a polygon feature's area more than 50
• Changing a feature's wof:name without storing the original wof:name as an alternative name
• Changing a feature's wof:name due to the original wof:name being wrong to begin with
• Giving a feature a new wof:parent_id
• Giving a feature a new wof:placetype
• Updating a feature's wof:hierarchy to include an updated wof:id
• Replacing or superseding a record (end of life event)

If a WOF record is updated due to a Significant Event, the following work is required:

• The feature's raw data (GeoJSON) should be duplicated into a new feature with a new wof:id.
• The newly duplicated feature receives a wof:supersedes value equal to that of the existing feature's wof:id.
• The existing feature receives a wof:superseded_by value equal to that of the new feature's wof:id.
• The existing feature receives a mz:is_current value equal to 0.
• If the existing feature was never correct to begin with, it will receive a new date (YYYY-MM-DD) in the edtf:deprecated property. Otherwise, the edtf:cessation property will be given a date (YYYY-MM-DD). This edtf date should equal the date when the feature was edited.

It is important to note that this list, as written today, may be incomplete or unable to capture the subtleties and demands of real-life. Additionally, we expect a decent amount of churn in Who's On First during the early days of the project which may require us to bend the rules in certain cases. However, this churn should settle as the database grows in size and allow us to possibly refine these rules.

Our Who's On First Life Cylce Document has more detailed information about Significant Events in relation to the wof:id.

Questions? Drop us an email.