I am currently playing with Apache mahout and reading book Mahout in Action and it confused me about the evaluator which we use in evaluation of recommender system and specifically i wanted to ask about AverageAbsoluteDifferenceRecommenderEvaluator
i.e when it results in 0
.
Does it means there is no error or does it means recommendation system is very bad?
Thanks.
0 means a perfect match.
RecommenderEvaluator returns MeanAverageError, representing how well the Recommender's estimated preferences match real values; lower scores mean a better match: 0 no error at all.