User-centered design and adaptive systems: toward improving usability and accessibility

Technology producers recognize the need for usability in interactive systems and the benefits that usable systems deliver. Nevertheless, guidance on how to ‘‘do’’ usability tends to be technique-centered, concentrating on specific approaches for designing or evaluating systems. In order to reach a consensus on how to build usercentered interfaces, no matter if they are hardware or software, it is necessary to specify some concepts. Usercentered design (UCD) is a design philosophy where the needs, desires and limitations of end users are under focus at all stages within the design process and development life cycle. In the case of software interfaces, UCD should be a common process in software development where typical UCD activities are broken down, in the better case, into four phases in the development life cycle: analysis, design, implementation and deployment. Products developed using the UCD methodology are optimized for end users, and emphasis is placed on how the end users interact with the product, instead of being forced to change their behavior to use the product. To achieve usability, design and evaluation are important tasks to carry out. How can technology producers at different levels of usability maturity, and with different criteria for usable systems, discover how to improve the usability of their systems? Standards have been developed in order to guide human-centered systems construction, such as ISO 13407:1999 and recently ISO 9241-210:2010 (Ergonomics of human-system interaction—Part 210: Human-centered design for interactive systems; (http://www.iso.org/iso/ home/store/catalogue_ics/catalogue_detail_ics.htm?csnum ber=52075), ISO 9241-161:2016 (Ergonomics of humansystem interaction—Part 161: Guidance on visual user interface elements; http://www.iso.org/iso/home/store/cata logue_ics/catalogue_detail_ics.htm?ics1=35&ics2=180&ic s3=&csnumber=60476). ISO 13407:1999 defines a process throughout a development life cycle, though does not indicate specific methods used for UCD. ISO 9241-210:2010 provides requirements and recommendations for human-centered design, principles and activities throughout the life cycle of computer-based interactive systems. Both standards are intended to be used by people managing design processes and are concerned with ways in which hardware and software components of interactive systems can enhance human–system interaction. ISO 9241-161:2016 describes visual user interface elements presented by software and provides requirements and recommendations on when and how to use them. This part of ISO 9241 is concerned with software components of interactive systems to make human–system interaction usable as far as the basic interaction aspects are concerned. Besides these standards, much effort has been made to create specific techniques for building user-centered interfaces; however, the challenge continues; technology evolution and user intuition demand for interactive and adaptable systems. An adaptive system changes to improve its performance by adjusting its operation based on the feedback from the users. An adaptive system infers the user goals and needs from multiple sources of information in terms of activity and interests. Research on adaptive systems should be addressed to identify new ways for enriching the user experience & Reyes Juárez-Ramı́rez reyesjua@uabc.edu.mx