Simply put, human factors involves work to make the environment work in a way that seems natural to people. This involves research in human performance and capabilities, anthropometrics, usability, and design. Although the terms human factors and ergonomic have only been widely known in recent times, the field's origin is in the design and use of aircraft during World War II.
Relevant Links: Human Factors and Ergonomic Society (www.hfes.org) Bad Human Factors Designs (www.baddesigns.com)