US Patent 8396876 Identifying reliable and authoritative sources of multimedia content

Embodiments are directed towards identifying authoritative sources of multimedia content useable in rank ordering class-dependent search-query results of multimedia content. In one embodiment, a citation model is employed for measuring or otherwise determining a strength of an authority to a content source. In one embodiment, a directed graph is constructed over a network of sources based on a propensity of one source to “cite” content provided by another source. In one embodiment, a random walk may be conducted across the network of sources to arrive at authority scores for each source in the network. In another embodiment, a machine-learning algorithm may be used to arrive at authority scores. The authority scores may then be applied for ranking, for example, search-query results, and/or retrieval purposes.