  Social network based approaches to person recommendations are compared to
interest based approaches with the help of an empirical study on a large German
social networking platform. We assess and compare the performance of different
basic variants of the two approaches by precision / recall based performance
with respect to reproducing known friendship relations and by an empirical
questionnaire based study. In accordance to expectation, the results show that
interest based person recommenders are able to produce more novel
recommendations while performing less well with respect to friendship
reproduction. With respect to the user's assessment of recommendation quality
all approaches perform comparably well, while combined social-interest-based
variants are slightly ahead in performance. The overall results qualify those
combined approaches as a good compromise.
