User-centered design

User-centered design (UCD) is a design framework in which the goals, characteristics, environment, tasks, and workflows of the people who will use a product are given sustained attention at every stage of the design process. Rather than shaping a product around what is convenient to build, UCD shapes it around how users actually think and act, so that users are not forced to change their behavior and expectations to accommodate the product.

The term was coined by Rob Kling in 1977 and was brought into the mainstream of human–computer interaction by Donald Norman’s research group at the University of California, San Diego. Norman’s 1986 collection User-Centered System Design and his 1988 book The Design of Everyday Things turned the idea into a widely cited set of principles for good design. Norman argued that well-designed products simplify the structure of tasks, make the system’s conceptual model visible, map intended results to required actions, and exploit the constraints a system already offers.

UCD is iterative. The canonical cycle has four phases that repeat rather than run once.

  • Specify the context of use. Identify the people who will use the product, why they will use it, and the environment they will use it in.
  • Specify requirements. Translate those needs into requirements the product must satisfy.
  • Create design solutions. Produce prototypes and refine them against the requirements.
  • Evaluate. Test with real or representative users through usability testing, feed the findings back into the design, and repeat.

Several artifacts help a team keep the design tied to real users rather than to the team’s own assumptions. A persona distills user research into a fictional but evidence-based archetype that the team can design for. A scenario describes a persona pursuing a goal, grounding design decisions in a concrete narrative. An essential use case abstracts a task into its intent and the system’s response, stripped of interface detail, so the designer can reason about what the user is trying to do before deciding how the interface should do it.

The framework is broader than any single technique. It draws on a family of related traditions, including the Scandinavian cooperative design movement, participatory design, and contextual design, all of which share the premise that the people who will live with a system should shape it. UCD is codified in ISO 9241-210, the international standard for human-centered design processes for interactive systems.

UCD is sometimes contrasted with approaches that center the system rather than the person. Tesler’s law captures the underlying trade-off. Every application has an irreducible amount of complexity, and UCD holds that the developer should absorb that complexity rather than push it onto the user. Designing for the whole user experience also means designing for users who are not the team’s default, which is why accessibility and A/B testing sit comfortably inside a UCD process as evaluation techniques for different audiences and different kinds of question.

See also

References

  • Kling, R. (1977). "The Organizational Context of User-Centered Software Designs". MIS Quarterly, 1(4): 41–52.
  • Norman, D. A. (1986). User-Centered System Design: New Perspectives on Human-Computer Interaction. CRC Press.
  • Norman, D. A. (1988). The Design of Everyday Things. Basic Books.
  • ISO 9241-210:2019. Ergonomics of human-system interaction — Part 210: Human-centred design for interactive systems. International Organization for Standardization.