"Freshness is everything" as far as the documents are concerned! That is what Google thinks about the whole issue concerning the "stale vs fresh contents" topic.
Bill Slawski has done a great job by giving these examples:
- The Constitution of the United States is an old document, but it's not stale. A news article about the "World Series" from 1918 may not be what a baseball fan wants to see when searching for "World Series" this October.
- While Babe Ruth is well known as a feared slugger for the New York Yankees, he's not as well remembered from his earlier days as a Boston Red Sox pitcher who threw a shutout in that 1918 World Series. Interesting information, but again, not what a searcher is likely to be looking for in an October 2008 search for "World Series."
A search engine might look at information from different sources to learn about:
- The age of a document
- The age of links leading to and from that document
According to Google,
Stale content refers to documents that have not been updated for a period of time and, thus, contain stale data (documents that are "no longer updated, diminished in importance, superceded by another document").
The staleness of a document may be based on:
- document creation date,
- anchor growth, traffic,
- content change,
- forward/back link growth, etc.
According to Google patent, there are 4 factors that determine the "stale" factor of a document:
- Query-based factor;
- Link-based criteria;
- Traffic – based criteria;
- User-behavior-based criteria
Query-based factor: are those factors that analyze as to which pages in SERPs are selected by users.
Link-based factor: analyzes the page backlinks.
Traffic – based criteria: If there is a large reduction in traffic, then it may mean that the content or the document is stale.
User-behavior-based criteria: if people spend too little time on the page, then chances are that the contents are not fresh.