Differentiating Your Design: A Visual Approach to Competitive Reviews
http://www.uxmatters.com/mt/archives/2009/04/differentiating-your-design-a-visual-approach-to-competitive-reviews.php

Hawley, Michael
UXmatters
2009

Abstract:

A common activity at the outset of many design projects is a competitive review. As a designer, when you encounter a design problem, it’s a natural instinct to try to understand what others are doing to solve the same or similar problems. However, like other design-related activities, if you start a competitive review without a clear purpose and strategy for the activity, doing the review may not be productive.