Ergonomics is focused on improving the health and productivity of humans, often by addressing the relationship between humans and the devices which they use every day. The design process which considers the needs and wants of users at each stage is known as user-centered design (UCD) or pervasive usability.UCD is not an action, but a process. Designers both anticipate and test human reactions to the product before it ever hits the market. While each person is different, the object is to create a design that will benefit the most people, rather than forcing every user to make adjustments in order to use the product.Both investigative and generative methods may be used in UCD. Common investigative methods include contextual inquiry and prototype testing, while generative approaches include diagraming and participatory design sessions. “Participatory design” does just what the name impliesit attempts to offer everyone involved a stake in the design process.UCD can be used for both physical products and for less concrete designs, such as that of company’s website. Designers ask themselves questions such as who will be using the product, what their experience levels will be, what functions they require, how they are expecting the product to work, and more. After coming up with the answers to these questions, the designers create a sample of the product and test it with ordinary customers. For web page designers, this would mean drawing up a sample website (or a reasonable facsimile) and observing users’ reactions. After the testing process, the designers take in the critiques and return to the drawing board.UCD seems to work especially well for instances when humans are interacting with computers or other machines. A website is just one example of something that might benefit from a user-centered approach. What about a web browser, or an operating system? We can also think outside of a personal computer and apply the same approach to a Blu-ray player, an MP3 player, a camera, etc.Donald Norman describes user-centered design in his book The Design of Everyday Things. This book was originally called The Psychology of Everyday Things, since it deals with how and why people differentiate between “good” and “bad” design.UCD offers benefits for both designers and consumers. If you’re interested in finding out more about the methodology of UCD, the Usability Professionals’ Association offers a detailed outline (with explanations) on its website.