id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-020936-k1upc1xu	Sanz-Cruzado, Javier	Axiomatic Analysis of Contact Recommendation Methods in Social Networks: An IR Perspective	2020-03-17		.txt	text/plain	5650	292	56	Recently, it has been shown that classical information retrieval (IR) weighting models – such as BM25 – can be adapted to effectively recommend new social contacts to a given user. In this paper, we analyze the reasons behind the effectiveness of IR approaches for the task of recommending contacts in social networks, through an exploratory analysis of the importance and validity of the fundamental IR axioms [13] . Interestingly, we find that while this is generally true, the axioms related to length normalization negatively impact the contact recommendation performance, since they interfere with a key evolutionary principle in social networks, namely preferential attachment [8] . 3. As the only difference between the original and the version of BM25 defined by Sanz-Cruzado and Castells is just the definition of the candidate length, it is straightforward to prove that all edge weight constraints and NDC are satisfied in the same way as they are for textual IR: NDC is unconditionally true, whereas all EWC axioms depend just on the condition:	./cache/cord-020936-k1upc1xu.txt	./txt/cord-020936-k1upc1xu.txt