Pros:
– well‐understood, works well in some domains, no knowledge engineering required
Cons:
– requires user community, sparsity problems, no integration of other knowledge sources,
no explanation of results
What is the best CF method?
– In which situation and which domain? Inconsistent findings; always the same domains
and data sets; differences between methods are often very small (1/100)
How to evaluate the prediction quality?
– MAE / RMSE: What does an MAE of 0.7 actually mean?
– Serendipity: Not yet fully understood
What about multi‐dimensional ratings?