Authority Threshold Algorithm (AT(k))

The idea behind AT(k) Algorithm is using only k highest authority weights instead of calculating average weight from every authority pointed by a hub. The parameter k is called authority threshold. A variant of an AT algorithm is MAX algorithm, where k=1, i.e. a hub is as good as the best authority it links to.

In general AT(k) algorithm uses the same formula as HITS. The difference is that when calculating the weight of a hub we consider top k authorities only, i.e. Fk(i) is a subset of outgoing links F(i). If the number of outgoing links |F(i)| is less or equal k than the AT(k) algorithm works exactly the same as HITS.