Human-Centered Design (HCD)
Human-centered design is an approach to building interactive systems around the people who will use them. ISO 9241-210 describes it as an iterative cycle: understand the context of use, specify user requirements, produce design solutions and evaluate them with users, repeating until the system meets those requirements.
Key takeaways
- Defined for interactive systems in ISO 9241-210, which spells it human-centred
- Four activities: context of use, user requirements, design solutions and evaluation
- Iterative: evaluation findings feed the next design round
- Broader than usability testing and more specific than design thinking
- Finds mismatches with real work before they become rework or use errors
What Human-Centered Design means
Human-centered design starts from who will use a system, what they are trying to do and where they do it, then designs to fit. It differs from designing around a feature list, where users first meet the product after it is built.
Why it matters: a problem found with users during design costs a sketch or a prototype to fix. The same problem found after release costs rework and support calls and, in clinical or regulated settings, the risk of a use error with real consequences.
Agnotic Technologies follows a human-centered process on the products it designs and builds for clients. The research methods behind it are covered on our UX research page, and how we run and rate usability tests is on our usability testing services page.
What are the principles of human-centered design?
ISO 9241-210 sets out six principles. Together they describe what makes a process human-centered, rather than a process that adds one user test at the end.
- The design is based on an explicit understanding of users, tasks and environments.
- Users are involved throughout design and development.
- The design is driven and refined by user-centered evaluation.
- The process is iterative.
- The design addresses the whole user experience.
- The design team includes multidisciplinary skills and perspectives.
How does it compare with UX design, usability and design thinking?
Usability is an outcome. ISO 9241-11 treats it as an outcome of use: how well specified users reach their goals in a given context of use.
Human-centered design is the process that aims for that outcome, along with accessibility and a good user experience.
UX design is the practice of shaping the experience itself: flows, screens and content. Done well, it follows a human-centered process.
Design thinking is a broader problem-solving approach, used for services and strategy as well as software. It shares the user focus but is not tied to the ISO activities or their outputs.
What does human-centered design look like on a software project?
Take a scheduling tool for clinic front-desk staff. Visits to observe the context of use show that staff book appointments while on the phone, often with a patient waiting at the desk.
That becomes a user requirement: a booking must be possible from the keyboard alone, in a few steps. Prototypes are tested with front-desk staff, and the findings change the layout before any production code is written.
What does each ISO 9241-210 activity produce in a software build?
The four activities repeat in cycles. The right column is the artifact a software team should expect from each one.
| Activity | The question it answers | What it produces |
|---|---|---|
| Understand and specify the context of use | Who uses the system, for which tasks, with what equipment and in what environment? | A context of use description: user groups, tasks, environments and constraints |
| Specify the user requirements | What must users be able to do, and how well? | User requirements with measurable criteria, linked to the context of use |
| Produce design solutions | Which design meets those requirements? | Task flows, wireframes and prototypes, from paper sketches to interactive versions |
| Evaluate the design against the requirements | Does the design work for real users doing real tasks? | Evaluation findings, rated by severity, that feed the next design round |
Facts and primary sources
ISO 9241-210:2019 provides requirements and recommendations for human-centred design principles and activities throughout the life cycle of computer-based interactive systems.
Source: ISO 9241-210:2019ISO 9241-220:2019 describes the processes and specifies the outcomes by which human-centred design is carried out within organizations, including the purpose, outcomes and work products of each process.
Source: ISO 9241-220:2019ISO 9241-11:2018 provides a framework for understanding usability, explains that usability is an outcome of use, and defines its key terms and concepts.
Source: ISO 9241-11:2018
Explore this on Agnotic
Where Human-Centered Design shows up in how we build.