How Do I Find Terms Without an is_a Parent?

There are two ways to do this:

Method 1: Use the "Has isa parent" filter

  1. Click the Advanced Settings tab of the Search Control.
  2. De-select every option but "Term filtering"
  3. Click the Term filter tab.
  4. Set up the filter as [not] [Self] [Has is_a parent]
  5. Press Search. A list of terms with no is_a parent will be displayed. Note that the ontology roots - having no parents at all - will also appear in this list.

Method 2: Link Filtering

Set up a link filter to only only display is_a links.

  1. Set your primary Ontology Editor Panel to use the GREEDY root algorithm by clicking the root algorithm selection button and picking "Show orphaned terms as roots" from the menu:
  2. Click the Advanced Settings tab of the Search Control.
  3. De-select every option but "Link filtering"
  4. Click the Link filter tab.
  5. Set up the filter as [Type] [Self] [ID] [equals] "OBO_REL:is_a"
  6. Click the Filter button.

Any term without an is_a parent will now appear as a root. This method has the advantage of being able to find terms without a parent of any specified type. To find part_of orphans, just use part_of instead of OBO_REL:is_a in the link filter setup.