It often happens that some business rules require us to boost the score of the selected items. In the book dataset, for example, if a book is recent, we want to give it a higher score. That's possible by using the IDRescorer interface, as follows:
- rescore(long, double) takes the itemId and original score as an argument and returns a modified score
- isFiltered(long) returns true to exclude a specific item from the recommendations, or false, otherwise
Our example can be implemented as follows:
class MyRescorer implements IDRescorer { public double rescore(long itemId, double originalScore) { double newScore = originalScore; if(bookIsNew(itemId)){ originalScore *= 1.3; } return newScore; } public boolean ...
