Reusing existing single-rating recommendation techniques. A huge number of
recommendation techniques have been developed for single-rating recommender
systems over the last 10-15 years, and some of them could potentially be extended
to multi-criteria rating systems. For example, neighborhood-based collaborative filtering techniques may possibly take into account multi-criteria ratings using the
huge number of design options that Manouselis and Costopoulou [51] suggest. As
another example, there has been a number of sophisticated hybrid recommendation
approaches developed in recent years [11], and some of them could potentially be
adopted for multi-criteria rating recommenders. Finally, more sophisticated techniques, e.g., based on data envelopment analysis (DEA) or multi-criteria optimization, could be adopted and extended for choosing best items in the multi-criteria
rating settings.