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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] Use interaction principles as evaluation prompts and prioritize them for the tasks and context of use.

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.

ISO 9241-110: Dialog Principles

ISO 9241-110 describes seven basic principles that ensure the user-friendly design of human-system dialogs.

Definition

Dialog principles are generally valid rules for the design of interactive systems. They apply regardless of technology or application and help to systematically improve usability.

The Seven Principles of Dialog

Apply the principles with heuristic evaluation, then use error models and user errors to identify preventable interaction failures.

1. Task Appropriateness

The system supports users in achieving their goals without unnecessary effort.

Example: An e-mail client allows quick filtering and sorting of incoming messages.

2. Self-Descriptiveness

The system is self-explanatory - every status and every option is clearly described.

Example: Buttons are clearly named (“Save”, “Cancel”), icons have tooltips.

3. Controllability

Users retain control over processes and can consciously trigger or undo actions.

Example: “Back” function in the order process or edit buttons on form fields.

4. Conformity with Expectations

The system behaves consistently and as expected by the target group - based on experience and conventions.

Example: A magnifying glass symbol stands for “Search” and opens an input field.

5. Fault Tolerance

Errors are detected, intercepted or can be corrected without serious consequences.

Example: Mandatory fields are checked before sending

6. Customizability

Users can customize the display or processes to suit their needs.

Example: Font size, language or color scheme can be configured individually.

7. Conduciveness to Learning

The system facilitates the learning process - through consistency, assistance and feedback.

Example: Instructions on first use (“Start tour”), clear status messages.

Application of the Principles

The dialog principles are particularly suitable for:

Conclusion

The seven dialog principles of ISO 9241-110 form a robust, technology-independent foundation for usable digital products.
They help to make interactions understandable, efficient and error-tolerant - all in the spirit of good UX.

Take Home Message

Good interactions are in line with expectations, controllable - and error-friendly.

Frequently asked questions (FAQ)

What is ISO 9241-110?
ISO 9241-110 is a standard that defines seven dialog principles for the user-friendly design of interactive systems. They are technology-independent and serve as a basis for good usability.
What are the seven dialog principles?
The standard names: task appropriateness, self-descriptiveness, controllability, expectation conformity, error tolerance, individualizability and learning facilitation.
What are the dialog principles used for in practice?
They are used in usability reviews, heuristic evaluations, style guides and for accessibility tests. The BITV also refers to ISO 9241-110.
How do the principles differ from heuristics?
Dialogue principles are normatively defined and internationally standardized, while heuristics are more practice-oriented guidelines. Both complement each other in usability evaluation.
Are the principles independent of each other?
No. They work together and should not be considered in isolation. A good design considers all seven principles in combination.
Why is expectation conformance important?
Because it ensures that a system behaves the way users expect it to. This reduces learning effort and errors and increases satisfaction.

Science corner: evidence data

Setting
Normative principles; expert inspection and user studies
Replication status
Theoretically or normatively grounded
Evidence level
High (E=5, T=4)
Key sources (APA)
  • International Organization for Standardization. (2020). Ergonomics of human-system interaction—Part 110: Interaction principles (ISO Standard No. 9241-110:2020). Open source
  • Prümper, J. (1997). Der Benutzungsfragebogen ISONORM 9241/10: Ergebnisse zur Reliabilität und Validität. In Software-Ergonomie ’97 (Berichte des German Chapter of the ACM, S. 253–262). Teubner. https://doi.org/10.1007/978-3-322-86782-7_21
  • Gediga, G., Hamborg, K.-C., & Düntsch, I. (1999). The IsoMetrics usability inventory: An operationalization of ISO 9241-10 supporting summative and formative evaluation of software systems. Behaviour & Information Technology, 18(3), 151–164. https://doi.org/10.1080/014492999119057
  • Bastien, J. M. C., Scapin, D. L., & Leulier, C. (1999). The ergonomic criteria and the ISO/DIS 9241-10 dialogue principles: A pilot comparison in an evaluation task. Interacting with Computers, 11(3), 299–322. https://doi.org/10.1016/S0953-5438(98)00038-1
Review date / version
2026-11-01 · 1.1
Next review
2027-11-01 (Review cycle: 12 months)

Last modified: 1 November 2026