| black box | A complex computer program that is poorly understood. Inputs and outputs can be observed, but there is no access to the process itself due to its confidential nature. For example, Google’s algorithm is a black box. |
| algorithm update | Changes that search engines make to certain signals of an existing algorithm. |
| null relevance | Noun phrase. The complete lack of internal or external factors that create a positive relevance score for a document in a search result in which the document is listed. |
| unnatural link profile | A site may have an unnatural link profile if the collection of unnatural links that are pointing to the site is very high. Sites that have an unnatural link profile have a high risk of being penalized by Google or other search engines. |
| blog network | Noun phrase. Any group of blogs (either hosted on large Websites or hosted on their own dedicated sites) that are used together for a common purpose. Some blog networks are enterprise assets (such as the AOL blog network including TechCrunch, Huffington Post, etc.). Some blog networks may be used to manipulate search engine results by Web spammers. A blog network differs from a blog farm (q.v.) in that writers upload their content directly to the network or to a central distribution platform. |
