Observing the User Experience: A Practitioner's Guide to User Research

Focus groups are structured group interviews that quickly and inexpensively reveal a target audience's desires, experiences, and priorities. Sometimes vilified by their association with dishonest marketing, they do not deserve the notoriety with which they are often treated. They are neither the panacea for curing bad products nor pseudoscientific voodoo used to justify irrational decision making. When guided by a good moderator, carefully analyzed, and appropriately presented, they are an excellent technique for uncovering what people think about a given topic and, especially, how they think about it. They reveal what people perceive to be their needs, which is crucial when determining what should be part of an experience and how it should be presented.
Originally called "focused interviews," focus groups were developed as a social research method in the 1930s, then refined as a method for improving soldiers' lives during World War II and embraced by marketing in the 1950s. As such, they're probably one of the oldest techniques for researching the user experience. A focus group series is a sequence of tightly moderated group discussions among people taken from a thin slice of a product's target audience. The discussions are designed to make people feel comfortable revealing their thoughts and feelings.
In software or Web site development, focus groups are used early in the development cycle, when generating ideas, prioritizing features, and understanding the needs of the target audience are paramount. They can tell you what features people value most highly and why they value them...