Answers are grounded in this paper and cite their sources.
Laboratory-based usability evaluations are often inadequate for the post-desktop-computer era. Field studies challenge us to design evaluations as quasi-experiments that don't assume perfect control and randomization. Such evaluations are expensive, but there are ways to reduce costs.
No takes yet. Share an insight, caveat, or question.
Antti Oulasvirta (2011) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: