Problem using picklists in computed field

[Kedevlin]

When a picklist field is pulling from a picklist that is "A list of values you define" (instead of records from a workspace), how is blank defined?

I'm created a computed field that shows "Incomplete" when certain picklist fields are blank and "Complete" when they are not blank.  Here's the formula I'm using:

case when PICKLIST_FIELD is null then 'Incomplete' Else 'Complete' END

This formula works when picklist type is "A list of records from a workspace" but does not work when picklist type is "A list of values you define". 

[dvirh · Accepted solution]

It depends on whether the item was saved with an empty Picklist or if the Picklist was added to the item after the item was created. In the former we use the value -999 and in the latter it would be null. As long as the Picklist was added to the workspace before any items were created, you can use the following computed field:

case when PICKLIST_FIELD=-999 then 'Incomplete' Else 'Complete' END

[Kedevlin]

That works, thank you!