Most likely it was this: McDougall, S. J. P., de Bruijn, O., & Curry, M. B. (2000). Exploring the effects of icon characteristics on user performance: The role of icon concreteness, complexity, and distinctiveness
I think I stumbled upon it while reading that era's GNOME HIG, that had some very similar thoughts about icons..
I think I stumbled upon it while reading that era's GNOME HIG, that had some very similar thoughts about icons..