  User ratings are widely used in web systems and applications to provide
personalized interaction and to help other users make better choices. Previous
research has shown that rating scale features and user personality can both
influence users' rating behaviour, but relatively little work has been devoted
to understanding if the effects of rating scale features may vary depending on
users' personality.
  In this paper, we study the impact of scale granularity and colour on the
ratings of individuals with different personalities, represented according to
the Big Five model. To this aim, we carried out a user study with 203
participants, in the context of a web-based survey where users were assigned an
image rating task.
  Our results confirm that both colour and granularity can affect user ratings,
but their specific effects also depend on user scores for certain personality
traits, in particular agreeableness, openness to experience and
conscientiousness.
