Wikipedia:Relevance

Relevance is a measurement of the degree to which material (fact, detail or opinion) relates to the topic of an article. Degree of relevance should be taken into consideration for most decisions on whether or not to include material. This is a goal statement intended to influence the application and evolution of policies, guidelines and editorial processes, not to restate current policies and guidelines. Material that is irrelevant or out of scope to an article's topic can unnecessarily bloat an article, making it difficult for a reader to remain focused, and can also give the material undue weight.

Directness of relevance is an important measure and consideration. A careful review of the actual statement(s) in the content is required to determine this. Keep in mind that in many cases (depending on the degree of expertise and objectivity of the source with respect to the statement) the "fact" is information about what the source's "take" or opinion is on the subject rather than information about the subject. For example, "Larry said that John is lazy" is not info about John, it is info about Larry's opinion and statement, even if Larry could sometimes be considered to be a source. Following is an approach to determine and name degrees of relevance and how to utilize the results:
 * Relevance level "High" – The highest relevance is objective information directly about the topic of the article. "John Smith is a member of the XYZ organization" in the "John Smith" article is an example of this.
 * Relevance level "Medium" – Information that is "once removed" is less directly relevant, should receive a higher level of scrutiny and achieve higher levels in other areas (such as neutrality, weight and strength and objectivity of the material and sourcing) before inclusion, but may still may be sufficiently relevant for inclusion. Including information about the XYZ organization in the John Smith article is a simple example of this. Another example is any substantially disputed characterization or opinion about the topic because it is info about somebody's opinion about John Smith rather than direct objective information about him. This includes situations where the opinion is expressed by a reliable source.
 * Relevance level "Lower" – Information that is "twice removed" should usually not be included unless the other considerations described above are unusually strong.  For example, in the above "John Smith" article, "Murderer Larry Jones was also a member of the XYZ organization."
 * Relevance level "Very low" – Information that is "three times removed" should not be included. For example, in the above "John Smith" article, "Murderer Larry Jones, also a member of the XYZ organization which John Smith belonged to, murdered 8 people."