Concept: Why does each tag need an ID when importing a taxonomy?

When creating a taxonomy via import, or updating one via re-import, the “id” column is required. In addition, it must be unique for every row. There are two reasons why such IDs are required.

Renaming tags

First, the IDs allow you to rename tags. When you upload a new version of the taxonomy, the IDs are compared to determine when a tag has been renamed or deleted.

For example, if you uploaded this taxonomy and used it to tag content in your courses:

Then you fixed the spelling to create this new version of the taxonomy, and re-imported it:

… because the ID of the first tag is the same (1), any content that was tagged with “Untied States” will now be fixed to show “United States”. But because the ID of the second tag has been changed, it is treated as a totally new tag - all instances of the “Candana“ tag will be deleted, and a new “Canada” tag will be created in the taxonomy, but no content will have that tag yet.

By keeping the ID the same (or not), you can control what will happen with new versions of the taxonomy - adding, renaming, moving, and deleting tags as needed. (Note that during the re-import workflow, you’ll get a chance to preview what changes will be applied before you finalize the update. That’s a good time to double-check that the right thing - rename or delete - is about to happen.)

If in doubt, a good rule of thumb is to never change the ID once a tag has been created, unless you’re certain you want to delete all occurrences of that tag and re-create a new similar tag from scratch.

Matching external systems/taxonomies

Second, the IDs can be used to keep your taxonomy in sync with an external system.

For example, you could have an airports taxonomy:

in this case, using the airport codes as the ID makes it easy to align the tags with other systems that reference airports, accounting for the fact that some airport names may be different (e.g. the Boston airport may be called “General Edward Lawrence Logan International Airport” or “Logan Airport”; the “Harry Reid International Airport in Las Vegas” was previously known as “McCarran International Airport”; etc.)

As another example, learning outcome standards often have IDs assigned to individual concepts. For example, the mathematics skill “Extend The Properties Of Exponents To Rational Exponents” has the ID “HS.N-RN.A.1“, which can be used to cross-reference it across various systems and publications. If you are creating a taxonomy related to learning outcomes, you can use these as the IDs.