As book designers, we're in the unique position of working on a wide array of topics in fiction and non fiction. I've also always kept a pretty diverse client list from very, very small to large trade publishers. After all, it's the small publishers that gave me my start.
About a year ago I worked on a title for CQ Press, a politics publisher in Washington, DC that publishes academic and reference books. The title I did for them, Controversies in Globalization, is a textbook (not my normal fare). It features 15 pairs of scholars and practitioners that directly address current questions in International Relations through brief "yes" and "no" pieces.
I knew that a contrast needed to be shown on the cover as this is a debate style book. The market is very different for textbooks. Mostly professors choose the books for their courses and are very familiar with competitive titles....a reason to produce a cover that is unique.
My first thought, of course, was a globe. As cliche as it seems, it did appear to be a necessary part of the book's content. So how to show it in a way that isn't completely obvious? These are my solutions...I showed 3 comps and the last one was chosen:
A red dividing line between the pieced globe suggests the contrast:
The final, which evokes a globe by the lines inside the circle, but also uses the speaking bubble. Black and white is the ultimate contrast: