RBO

We measure the Rank-Biased Overlap (RBO) between two ranked recommendation lists. RBO is a similarity metric designed to compare ranked lists while placing higher importance on the top of the rankings. It allows for evaluating the agreement between two recommendation sets even when the lists are of different lengths or have incomplete overlap.

The parameter p controls the top-weightedness of the metric — higher p values give more weight to deeper ranks, while lower p values emphasize top-ranked items.