Effectiveness and efficiency have come to be blurred in the mind. They are, however, quite different from a usability perspective. Efficiency is all about speed. How fast can the user get the job done?
iso 9241 11 usability pdf download
Usability is more than just ease of use. You need to ensure designs are efficient, effective, engaging, easy to learn and error tolerant if you want them to succeed. Of course, there are limitations on the value of usability, and sometimes trade-offs have to be made to ensure economic viability, for example. However, when there is no such conflict, usability should be the priority.
Usability is a term used to denote the ease with which people can employ a particular tool or other human-made object in order to achieve a particular goal. [...] In human-computer interaction and computer science, usability usually refers to the elegance and clarity with which the user interface of a computer program or a web site is designed. The term is also used often in the context of products like consumer electronics, or in the areas of communication, and knowledge transfer objects (such as a cookbook, a document or online help). It can also refer to the efficient design of a mechanical objects such as a door handle or a hammer. (Wikipedia: Usability - retrieved 17:30, 9 June 2006)
Usability can also refer to the methods of measuring usability and the study of the principles behind an object's perceived efficiency or elegance. (Wikipedia: Usability - retrieved 17:30, 9 June 2006 )
In other words, usability - even in the eye of hardcore usability specialists such as Nielsen - transcends nowadays usability and expands into usefulness or something that is often called user experience.
Most usability and user experience studies seem to focus on commercial web sites and/or sites with easy content structure. Complex web sites (e.g. large hypertexts or sophisticated web applications) need to be learned since not everything can be "dumbed down" for one shot users. Focus then must include learnability, which is often confused with familiarity in traditional usability testing...
Usability is a factor in all design stages (e.g. requirements, design, implementation, testing, evaluation). I.e. usability guidelines are considered early in the process and early design prototypes like wireframes are also subject to usability testing.
It is important to understand that good usability testing is not asking for opinions like "do you like the system", "can you understand X", but giving persons carefully crafted tasks to do. Typically, such user sessions are recorded and/or monitored by observers and then analyzed in detail. However, more lightweight methods do exist and some dimensions of usability (e.g. user experience/emotional response/satisfaction) may be measured by questionnaires.
It is important to start usability testing early in the design process. {{quotationTesting one user early in the project is better than testing 50 near the end." - Steve Krug, Don't Make Me Think cited in the Usability Test Planning of NASA's usability toolkit
The International Standard ISO 9241-11 is frequently referenced as a source definition for Usability. In the past 10 years, a number of standards that relate to Usability have been published. In this essay, I highlight the ISO standards that focus on human-centered design and quality information processes, and I identify the technical committees responsible for the development of these standards. The ISO process capability model and framework for assessment provides a structure for examination of organizational UX Maturity. As our UX processes become embedded in product life cycle development, UX standards may increase in importance in areas such as certification, regulatory approval, and interoperability. Some barriers continue to deter the widespread use of ISO standards, and these include cost and complex language.
In the first issue of the Journal of Usability Studies, Mary Theofanos and Whitney Quesenbery presented a paper on best practices for reports of formative usability evaluations (2005). The practical takeaway indicated that there was little guidance available for these types of reports, and there was significant variation in reporting. Since 1998, Rolf Molich has championed 10 Comparative Usability Evaluation (CUE) studies to examine reproducibility in usability evaluations with practicing professionals and academics (n.d.). A consistent theme through the CUE studies has been the variability in practice and reporting (Molich, 2018). While experienced practitioners are able to identify usability issues and make corresponding recommendations for solutions, the variability in findings and how reporting is carried out suggests the need for stronger guidance.
Consider the last two items as co-dependent, where guidance on usability and quality measures can be tied to design processes. In this essay, I would like to highlight some relevant standards and then link how these can support UX maturity and UX certification.
You can glean some additional information from the query results such as the Technical Committee responsible for the standard, version number, edition, and number of pages. Standards are also organized by the International Standard Catalogue (ICS), which consists of numbered groupings by area. For ISO 9241-11:2018, these are
The focus of ISO/IEC JTC 1/SC 7 is on Software and Systems Engineering. This joint technical committee has a scope that addresses standardization of processes, supporting tools, and supporting technologies for the engineering of software products and systems. A Joint Working Group (JWG) is where members of two different subject areas work together, and this occurs in JWG 28. This working group has been responsible for a series of publications related to Common Industry Formats (CIFs) for various usability related reports and processes.
More details on sub-stages can be found on the ISO website. Standards in the Enquiry Stage are open for comments by members of the public through national bodies. On the International Harmonized Stage Codes page, you can view the stages in a summary table and download a printable version. Subject matter experts, representing national bodies/organizations, can contribute and vote as documents are developed through a consensus review process.
Looking at the information on ISO 9241 you can learn that the current 2018 standard replaced the 1998 standard. The 60:60 Stage designation indicates that this particular version has successfully passed through the earlier development and review stages. ISO standards are examined for currency every five years. Depending on the significance of the updates, the stages 00 through 50 ensure input, collaboration, and consensus before publication.
The ISO standards 9241-220 and 9241-221 provide guidance on process examination specific to human centric design. As you can see in the standard titles, all three are grouped under Ergonomics of human and system interaction. They each have ICS identifiers (ISO Standards Catalog) that indicate the responsibility of Ergonomics (13.180) and IT and other peripheral equipment (35.180).
The processes are described from the viewpoint of those responsible for the analysis, design and evaluation of the human use of interactive systems. The process descriptions include the purpose, benefits, outcomes, typical activities and work products for each process, and are for use in the specification, implementation, assessment and improvement of the activities used for human-centred design and operation in any type of system life cycle. They can also provide the basis for professional development and certification (ISO Standard No. ISO 9241-220:2019, Abstract).
Process Performance Indicators refer to Level 1; Process Capability Indicators refer to Level 1 and above. The ISO/IEC 9241-221 standard is currently under development and considerable detail is provided on process purpose, process benefit, process outcomes, best practices, input work products, and output work products. Detailed appendixes highlight examples and labeling conventions. Table 3 presents the recommended ISO 33020 rating scale.
The NN/Group (Pernice, 2021) describes organizational behaviors that are observed at each stage. While the Dialog Design (n.d.) maturity model is derived from the ISO 33020 Standard. Descriptive UX characteristics are identified for each level such that performance indicators can then be used for compliance purposes. A competency scale, using UX language/vocabulary, results in a well-structured assessment framework. Such approaches parallel what is covered in ISO/IEC 33020 and ISO 9241-221. These are just two examples where UX maturity models are promoted for examining organizational capability and consistency.
The need for process-driven design systems with evaluation and reporting requires effort and resources. The variety of usability test methods and complexity of product life cycle development contribute to variability in the quality and repeatability of UX outcomes. For organizations with a strong focus on process, the ISO standards in the 25000 SQuaRE series and the 9241-210, -220, -221 provide guidance on quality measures. These standards have been developed to support industry and national bodies. As our UX products become embedded in complex systems, these standards can take on increasing importance and support organizations in assessing their process capability and maturity.
A deterrent to the widespread use of standards is the cost associated with accessing ISO documents. This is compounded by the fact that standards documents are difficult to read and interpret. Unless you are involved in a highly regulated industry, you may not be aware of these standards. The ISO 9241-11 is often mentioned as the source for Usability definitions, but I think few practitioners are aware of the many related standards now in place.
International Organization for Standardization. (2018). Ergonomics of human-system interaction Part 11: Usability: Definitions and concepts (ISO Standard No. ISO 9241-11:2018). ::text=ISO%209241%2D11%3A2018%20provides,services%20(including%20technical%20and%20personal 2ff7e9595c
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