This change boils down to a change of label (and maybe salary), not necessarily a change of role or activity. As a technical communicator, my friend is already well experienced in usability: usability & human factors professional is one of the jobs that technical communicators do.
The short answer is (maybe)...
- Both tech writers and UX professionals work to make an object easier for people to use.
- For both, their raison d'etre is to put the user first. 'Write for the reader' is usability incarnate.
- The UX professional works on the item itself as well as the documentation.
- The tech writer works on the documentation alone, but applies UX principles with words, layout, formatting and IE.
But in real life that short answer is at best a gross generalization, at worst a lie.
For example: if a tech writer is called in early in the product development process, he or she can contribute a great deal of UX expertise, thus saving many problems down the track. The more a product can be used instinctively, the less it needs to be explained.
So a technical writer, by acting as a UX professional alongside designers, can lessen the technical writer's load down the track. Why? Because fewer words will be needed. After all, on the whole, the more we explain, the less people understand and and the less they remember.
If you have read this far and are saying 'Waaaaa?', no surprise. Angels are dancing on pin-heads here! Anyone wanting to steer technical writing career towards a usability career should just take some practical steps, as my friend is already doing:
- Look for opportunities to increase your UX expertise and reputation.
- Reshuffle your resume CV to highlight the UX work you have been doing for years.
- Apply for UX jobs.