I recall a paper from GDC many years back that studied the perception of immersion and they measured and ranked maybe a dozen different factors. Graphics and visuals were surprisingly low on the list. The number one thing was the player’s sense of identity and clear understanding of their goals. Players tended to correlate realism with high immersion too.
That’s definitely in the same realm, but not the one I was thinking of. I believe I’m thinking of something maybe 10 years earlier, it had multiple authors, at least one woman, and some of the authors were psychology researchers who were into games. I’d wouldn’t be surprised if this is a theme and avenue of research that has come up many years at GDC.
