Usability engineering is a field that focuses on the interaction between humans and computer interfaces. In the most basic of terms, a usability engineer works on making human operators happy with the experience of using the interface. This is done through simplifying common tasks, making the interface easy to read and understand and automating technical or complicated tasks. In general, people with a primary degree in a human science and a secondary in a technical field perform most usability engineering, but some institutions have degrees in the actual subject.
While some usability engineering focuses on mechanical interfaces, such as those in a car or piece of heavy machinery, the bulk of the study goes to electronic interfaces. These interfaces may be a standard computer operating system or a specialized system on a cash register, automatic teller machine or purpose-specific piece of software.
The most important factor in usability engineering is comfort. It is far more important that a user be comfortable with an interface than have access to every conceivable option. For example, if a user interface has too many options on the main page, a user may feel overwhelmed by choices. If a usability engineer puts only the most important options on the main page and the rest on easily accessible subpages, the user will be less overwhelmed and more comfortable. While it may be more efficient to have things in one place, it is less friendly.
This most common method used by usability engineers is a hands-on study. In these cases, an engineer will give a person access to the interface, often with little or no instruction as to how to use it. The subject will be given a series of tasks to complete using the interface. After completing or failing the tasks, the engineer will ask the subject questions about the interface, finding out which areas worked and which didn’t. Most hands-on studies have several participants to keep one subject from skewing the data.
Originally, people with human-related degrees, such as psychology or anthropology, did most usability engineering. These people generally had minors or secondary interest in technical fields. This combination gave them the insight into both human behavior and machine operation that was needed for the field. While this combination is still very common, many new usability engineers have gone through directed programs that focus on usability specifically. In addition, many technical training courses are covering usability to a much greater extent than before, giving the interface designers the tools necessary to direct their own testing.