systems engineering Systems engineering is an interdisciplinary field of engineering and engineering management that focuses on how to design, integrate, and manage complex systems over their enterprise life cycle, life cycles. At its core, systems engineering util ...

, the system usability scale (SUS) is a simple, ten-item attitude

Likert scale A Likert scale ( , commonly mispronounced as ) is a psychometric scale commonly involved in research that employs questionnaires. It is the most widely used approach to scaling responses in survey research, such that the term (or more fully the ...

giving a global view of subjective assessments of

usability Usability can be described as the capacity of a system to provide a condition for its users to perform the tasks safely, effectively, and efficiently while enjoying the experience. In software engineering, usability is the degree to which a soft ...

. It was developed by John Brooke at

Digital Equipment Corporation Digital Equipment Corporation (DEC ), using the trademark Digital, was a major American company in the computer industry from the 1960s to the 1990s. The company was co-founded by Ken Olsen and Harlan Anderson in 1957. Olsen was president unt ...

in the UK in 1986 as a tool to be used in

usability engineering Usability engineering is a field that is concerned generally with human–computer interaction and specifically with devising human–computer interfaces that have high usability or user friendliness. It provides structured methods for achieving ...

electronic office The electronic office, or e-office, was a term coined to cover the increasing use of computer-based information technology for office work, especially in the 1980s. It was a popular marketing buzzword during that era, but is no longer so widely use ...

systems. The usability of a system, as defined by the ISO standard

ISO 9241 ISO 9241 is a multi-part standard from the International Organization for Standardization (ISO) covering ergonomics of human-computer interaction. It is managed by the ISO Technical Committee 159. It was originally titled ''Ergonomic requiremen ...

Part 11, can be measured only by taking into account the context of use of the system—i.e., who is using the system, what they are using it for, and the environment in which they are using it. Furthermore, measurements of usability have several different aspects: * effectiveness (can users successfully achieve their objectives) * efficiency (how much effort and resource is expended in achieving those objectives) * satisfaction (was the experience satisfactory) Measures of effectiveness and efficiency are also context specific. Effectiveness in using a system for controlling a continuous industrial process would generally be measured in very different terms to, say, effectiveness in using a text editor. Thus, it can be difficult, if not impossible, to answer the question "is system A more usable than system B", because the measures of effectiveness and efficiency may be very different. However, it can be argued that given a sufficiently high-level definition of ''subjective'' assessments of usability, comparisons can be made between systems. SUS has generally been seen as providing this type of high-level subjective view of usability and is thus often used in carrying out comparisons of usability between systems. Because it yields a single score on a scale of 0–100, it can be used to compare even systems that are outwardly dissimilar. This one-dimensional aspect of the SUS is both a benefit and a drawback, because the questionnaire is necessarily quite general. Recently, Lewis and Sauro suggested a two-factor orthogonal structure, which practitioners may use to score the SUS on independent Usability and Learnability dimensions. At the same time, Borsci, Federici and Lauriola by an independent analysis confirm the two factors structure of SUS, also showing that those factors (Usability and Learnability) are correlated. The SUS has been widely used in the evaluation of a range of systems. Bangor, Kortum and Miller have used the scale extensively over a ten-year period and have produced normative data that allow SUS ratings to be positioned relative to other systems. They propose an extension to SUS to provide an adjective rating that correlates with a given score. Based on a review of hundreds of usability studies, Sauro and Lewis proposed a curved grading scale for mean SUS scores.

References

External links

System Usability Scale (SUS) Score Calculator
{{Engineering approaches Computer-related introductions in 1986 User interfaces Systems engineering Human–computer interaction Qualitative research Survey methodology Usability

References

Further reading

External links