Overview
ISO 9186-1:2014 - Graphical symbols - Test methods - Part 1: Method for testing comprehensibility - defines a standardized procedure for evaluating how well a graphical symbol communicates its intended meaning without explanatory text. The standard provides a repeatable comprehension test that yields a quantitative measure (percentage correct) of how readily people understand a symbol variant, supporting the development and selection of symbols for public information, safety signage, equipment, and user interfaces.
Key topics and requirements
- Purpose: Measure the extent to which a symbol variant conveys its intended referent (meaning) when shown alone, encouraging symbols that are understandable without supplementary text.
- Principle: Present each respondent with one variant per referent and ask, “What do you think this symbol means?” (and, where relevant, “What action should you take?”). Score variants by the percentage of correct responses.
- Test materials:
- Provide one variant per test page (A5 or larger) using black on white unless colour is integral to coding.
- Include contextual information (word or photograph) adjacent to the symbol in a language fluent to the respondent.
- Prepare instruction, respondent self-report, and example pages in the respondent’s language.
- Test administration:
- Use printed or computer screen presentation (internet-based testing permitted with guidance).
- Limit the number of variants for a single referent (recommended maximum three).
- Ensure consistent image quality and legibility across presentations and countries.
- Respondents & scoring:
- Capture free-text interpretations, including “Don’t know.”
- Categorize and analyze responses to determine the most comprehensible variant and report results (percent correct).
- Preliminary steps:
- Align symbol design with relevant design principles and submission requirements of standards bodies before testing.
Practical applications and who uses it
ISO 9186-1 is used by:
- Standards committees (ISO/TC 145 and others) assessing candidate public information and safety symbols.
- Signage and UX designers validating symbol comprehensibility.
- Safety managers and regulatory bodies verifying that symbols will be understood by intended audiences.
- Manufacturers and product teams creating equipment markings without relying on text.
- Usability researchers running cross-cultural comprehension studies.
Benefits include evidence-based symbol selection, improved international legibility, and reduced need for multilingual explanatory text.
Related standards
Keywords: ISO 9186-1, graphical symbols, comprehensibility test, symbol testing, signage standard, public information symbols, safety signs, ISO standard.
