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Evidence rating

Effect score (E): 5/5 Evidence for the underlying principle or measurement method.

Transfer score (T): 4/5 Evidence for reliable results in digital product practice.

Evidence level: High

[Plausible based on UX research] Involve users early and repeatedly, and feed evaluation findings into concrete design iterations.

Scale and rating rules

Effect score: 5 established · 4 robust · 3 context-dependent · 2 weak · 1 preliminary.

Transfer score: 5 practice-proven · 4 field-supported · 3 partially supported · 2 plausible · 1 hypothesis.

Without a robust scientific or normative source, E is capped at 3. Blog and agency opinions support at most T=2. If evidence conflicts, the more conservative score applies until justified otherwise.

Evidence level: High = E ≥ 4 and T ≥ 3; Moderate = E ≥ 3; Preliminary = E ≤ 2 or T ≤ 1.

User-Centered Design Process

The user-centered design process (according to ISO 9241-210) describes how systems are developed that meet real needs - through iteration, participation and contextual understanding.

Definition

A user-centered design process ensures that interactive systems are developed for and with the user - systematically, iteratively and contextually.

The four main activities according to ISO 9241-210

1. Understand the context of use

  • Who uses the system?
  • For what, when and under what conditions?
  • What are the needs, goals and restrictions?

2. Derive usage requirements

  • Welche Aufgaben müssen unterstützt werden?
  • Which functions, data and forms of interaction are required?

3. Develop design solutions

  • Sketches, prototypes, wireframes
  • Visual design, interaction concepts
  • Involvement of real users

4. Evaluate design solutions

  • Usability-Tests
  • Heuristic evaluation
  • A/B tests, field studies, interviews

Principles of user-centered design

According to ISO 9241-210:

Practical example

A team is developing a medication reminder app for older people:

Conclusion

The user-centered design process is not an additional effort - but a necessity for sustainable UX quality.
It provides the methodological basis for all successful UX projects.

Take Home Message

Systems are only as good as their understanding of the context of use - UX starts with listening.

Frequently asked questions (FAQ)

What is the user-centered design process?
It is an iterative approach according to ISO 9241-210, which ensures that systems are developed for and with the users - based on real needs and usage contexts.
What are the main activities of the process?
Four steps: Understanding the context of use, deriving user requirements, developing and evaluating design solutions. These are repeated several times.
Why is iteration so important?
Every evaluation can uncover new requirements. Iteration prevents problems from being identified late and reduces the cost of rework.
How are users involved in the process?
Through interviews, field studies, usability tests and feedback in all phases - from requirements elicitation to the evaluation of prototypes.
What are the benefits of a user-centered process?
It increases usability, reduces operating errors, increases acceptance and reduces development and support costs in the long term.

Science corner: evidence data

Setting
Iterative product development; evaluation in context of use
Replication status
Mixed findings
Evidence level
High (E=5, T=4)
Key sources (APA)
  • International Organization for Standardization. (2019). Ergonomics of human-system interaction—Part 210: Human-centred design for interactive systems (ISO Standard No. 9241-210:2019). Open source
  • Gould, J. D., & Lewis, C. (1985). Designing for usability: Key principles and what designers think. Communications of the ACM, 28(3), 300–311. https://doi.org/10.1145/3166.3170
  • Kujala, S. (2003). User involvement: A review of the benefits and challenges. Behaviour & Information Technology, 22(1), 1–16. https://doi.org/10.1080/01449290301782
  • Jokela, T., Iivari, N., Matero, J., & Karukka, M. (2003). The standard of user-centered design and the standard definition of usability: Analyzing ISO 13407 against ISO 9241-11. Proceedings of the Latin American Conference on Human-Computer Interaction, 53–60. https://doi.org/10.1145/944519.944525
Review date / version
2026-11-01 · 1.1
Next review
2027-11-01 (Review cycle: 12 months)

Last modified: 1 November 2026