Design is the visual arrangement of your page. The key idea is to establish a visual logic—the same kind of information always looks the same way and appears in the same place (page numbers are italicized in the upper right corner, for instance). The two key concepts in format are heads and chunks.

Visual logic. Visual logic establishes your credibility, because you demonstrate that you know enough about the topic and about communicating to be consistent. Visual logic helps your audience to see the "big picture" of your topic, and as a result they grasp your point more quickly.

Heads and chunks. Heads are words or phrases that tell the content of the next section. Heads should inform and attract attention—use a phrase or ask a question; avoid cryptic, one-word heads.

Heads have levels—one or two are most common; more than four is rare. The levels should look different and make their contents helpful for readers. Most audiences normally expect that bigger and closer to the left symbolize higher levels than smaller and indented. However, when centered heads are present, by tradition, they always indicate the highest level.

Chunks are any pieces of text surrounded by white space. Typically, readers find a topic presented in several smaller chunks easier to grasp than one longer chunk.

Chunks should relate to organization. For instance, you can indent a chunk, thus indicating that the topic in that chunk is subordinate to the one above it—as often happens in lists.