The Five W's: An Old Tool for the New Task of Task Analysis
http://www.ingentaconnect.com/content/stc/tc/1996/00000043/00000002/art00004
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  peer-reviewed

Hart, Geoffrey J.S.
Technical Communication Online
1996

Abstract:

An audience pays attention to your attempts at communication because they have certain needs that they expect you to solve. As journalists have long known, it's possible to meet the majority of an audience's need for information by answering five 'W' questions: what, who, where, when, and why. Although this approach is a core element of journalism, it has obvious applications to technical communicators, who must create information in the context of meeting an audience's needs.