What is the difference between a "technologist" and a "technician"?
It sounds a lot like title inflation to me, to avoid the perception of a technician as a someone who simply applies technological solutions in a more or less routine, rote manner.
As for "technologist" itself, Dictionary.com says it dates back to the mid-19th century. I would say that it sounds like a broad term that can encompass technicians, engineers, inventors, (technical) evangelists, etc, but most of the usages I've found could just as easily have used "technician". So I'm sticking with simple job title inflation as the explanation for the popularity of the word, and technologist=technician.
I think a generalization of the dictionary definitions would be:
- a technician works primarily on things
- a technologist works primarily on technology
The object of the technician / technologist is the key.
So looking at the Wikipedia entries, one could argue that
- an Architectural technologist specializes in technology, not architecture, so technologist is appropriate.
- a Cardiovascular technologist specializes in cardiology, not technology, so technician is appropriate.
- an Engineering technologist specializes in technology (more so than engineering), so technologist is appropriate.
- a Radiologic technologist specializes in radiograms, not technology, so technician is appropriate.
One could also argue that if the person depends on a specific technology (x-ray machine, Doppler heart monitor), then s/he is a technician. If that person needs to develop or deploy or implement a technology, then s/he is a technologist.
Applying this thought,
- an Architectural technologist designs technology for new buildings, so technologist is appropriate.
- a Cardiovascular technologist is dependent on his/her Doppler heart monitor, so technician is appropriate.
- an Engineering technologist implements technology in the field of engineering, so technologist is appropriate.
- a Radiologic technologist is dependent on his/her x-ray machine or Dual-energy X-ray absorptiometry instrument or MRI, so technician is appropriate.