User-Centered Systems Design: A Brief History - Foundations for Designing User-Centered Systems - page 44

expert varies in design. The nature and level of involvement depends on the ethos of the
design setting (the relative importance of usability issues and the degree of focus on
supporting the user). We will deal with more HCI research in upcoming chapters.
2.3 Standards, Principles, and Guidelines
All of the disciplines mentioned above have a goal of answering specific research
questions using experimental and observational methods. For example a research
project may ask:
• Is this chair comfortable over an 8 h working day?
• Can the user get their task done with this application?
• Is the font used in this interface readable?
• Have we made the most important information in this interface stand out?
• Is this interface esthetically appealing to the user demographic I am interested
in?
• Will the user get the information they need in a timely fashion if there is an
emergency?
It is not always possible to carry out this research to answer questions of this
sort oneself, so researchers turn to lessons learned from previous studies that are
codified as standards, principles, and guidelines that can be applied to the problem
situations they encounter.
Formal standards are generated by experts. They are intended to capture the
agreed-upon wisdom and best practices of the field. Once created, they offer a
common vocabulary for designers/developers and, ideally, result in systems that
are more consistent for users, more easily inter-operable, and easier to integrate. In
the design world, standards tend to be concerned with human adaptability and
human variability. They are prescriptions for safe, acceptable designs, detailing the
limits outside which the user may suffer from stress, and accidents may be caused.
Standards are and can become part of the law. For example, British Standard BS
5330 deals with the relationship between sound levels in the workplace and the
incidence of hearing loss.
Principles are prescriptive and specify general theoretical ideas that can underpin
design decisions. They do not specify the limits of human capabilities like standards
do and tend to be more general than guidelines. (Note that although we make this
distinction between guidelines and principles, the ergonomics literature generally
does not.) Ideally, such principles are encapsulations of theoretical insights that have
been derived from extensive data gathering and testing. For example, Norman
( 1988 , 2013 ) outlines a set of principles that designers should consider, e.g., making
things visible and providing feedback. Norman's principles are based on his theory of
action and interaction (noted further in Chap. 12 ) . In particular, he emphasizes that
the state of the system should be visible, that feedback on user's actions should be