[0087] Traffic
[0088] According to an implementation consistent with the principles of the invention, information relating to traffic associated with a document over time may be used to generate (or alter) a score associated with the document. For example, search engine 125 may monitor the time-varying characteristics of traffic to, or other "use" of, a document by one or more users. A large reduction in traffic may indicate that a document may be stale (e.g., no longer be updated or may be superseded by another document).
[0089] In one implementation, search engine 125 may compare the average traffic for a document over the last j days (e.g., where j=30) to the average traffic during the month where the document received the most traffic, optionally adjusted for seasonal changes, or during the last k days (e.g., where k=365). Optionally, search engine 125 may identify repeating traffic patterns or perhaps a change in traffic patterns over time. It may be discovered that there are periods when a document is more or less popular (i.e., has more or less traffic), such as during the summer months, on weekends, or during some other seasonal time period. By identifying repeating traffic patterns or changes in traffic patterns, search engine 125 may appropriately adjust its scoring of the document during and outside of these periods.
[0090] Additionally, or alternatively, search engine 125 may monitor time-varying characteristics relating to "advertising traffic" for a particular document. For example, search engine 125 may monitor one or a combination of the following factors: (1) the extent to and rate at which advertisements are presented or updated by a given document over time; (2) the quality of the advertisers (e.g., a document whose advertisements refer/link to documents known to search engine 125 over time to have relatively high traffic and trust, such as amazon.com, may be given relatively more weight than those documents whose advertisements refer to low traffic/untrustworthy documents, such as a pornographic site); and (3) the extent to which the advertisements generate user traffic to the documents to which they relate (e.g., their click-through rate). Search engine 125 may use these time-varying characteristics relating to advertising traffic to score the document.
[0091] In summary, search engine 125 may generate (or alter) a score associated with a document based, at least in part, on information relating to traffic associated with the document over time.
[0092] User Behavior
[0093] According to an implementation consistent with the principles of the invention, information corresponding to individual or aggregate user behavior relating to a document over time may be used to generate (or alter) a score associated with the document. For example, search engine 125 may monitor the number of times that a document is selected from a set of search results and/or the amount of time one or more users spend accessing the document. Search engine 125 may then score the document based, at least in part, on this information.
[0094] If a document is returned for a certain query and over time, or within a given time window, users spend either more or less time on average on the document given the same or similar query, then this may be used as an indication that the document is fresh or stale, respectively. For example, assume that the query "Riverview swimming schedule" returns a document with the title "Riverview Swimming Schedule." Assume further that users used to spend 30 seconds accessing it, but now every user that selects the document only spends a few seconds accessing it. Search engine 125 may use this information to determine that the document is stale (i.e., contains an outdated swimming schedule) and score the document accordingly.
[0095] In summary, search engine 125 may generate (or alter) a score associated with a document based, at least in part, on information corresponding to individual or aggregate user behavior relating to the document over time.