© 2015 European Association of Personality Psychology. There is a well-established tradition of assessing personality traits, and some of its principles may have parallels in assessment of situations. Trait measures are interpreted in terms of norms; situation assessments may require multiple judges to control perceiver effects. Internal consistency is monitored in trait research; inter-rater reliability should be reported in situation research. Personality scales typically assess traits rather than states; situational assessment might profitably concentrate on recurrent rather than one-time situations.