Specifically, Section 6.1 on "Purpose, Audience, Tone, and Content" or "Writing with Outside Evidence" found in composition textbooks like Writing for Success.

This query could refer to several different academic or technical topics. To provide the right write-up, could you clarify if you mean:

The chapter 6.1 What is User Experience Design? from Technical Writing Essentials, which connects rhetorical ideas to UX practice.