User Testing

Three to five testers using system, explaining their decisions out loud. Observer records observations without offering help. Testers should be representative of target audience. Identify trends in user behaviour during use of system to spot problems. System can be prototype or existing system, either way it needs to be operational.

Ten Usability Heuristics

Web Usability: Usability Inspections Ten Usability Heuristics Ten general principles for user interface design – more rules of thumb than specific usability guidelines, hence “heuristic”. Visibility of system status – the system should always keep users informed about what is going on, through appropriate feedback within reasonable time. Match between system and the real world – the system should speak the […]

Heuristic evaluation

Web Usability: Usability Inspections Heuristic evaluation A heuristic technique (/hjᵿˈrɪstᵻk/; Ancient Greek: εὑρίσκω, “find” or “discover”), often called simply a heuristic, is any approach to problem solving, learning, or discovery that employs a practical method not guaranteed to be optimal or perfect, but sufficient for the immediate goals. (Wikipedia, 2017) In context of usability, heuristic evaluation is examination of interface […]

Nielsen’s views

Jakob Nielsen – five concepts: Learnability – system ease of use. Efficiency – how well system maps interface to user interaction. Memorability – how easy it is for users to remember how to do something. Errors – how well errors are handled and prevented. Satisfaction – user satisfaction with system. Top ten web design mistakes according to Nielsen: 1996 Using […]

Design for usability

User Centred Design – identify users needs & requirements. Define purpose of website. Perform User Requirements Analysis – define users assumptions & future behaviour on site. Implement these steps when designing & producing objects & functions. Become familiar with general rules & guidelines for website usability such as: Web Site Usability Handbook by Mark Pearrow Web Standards Project available at […]


Generic term – design features enable=ing something to be user-friendly. Measure of quality of user experience with product or system such as: website mobile device software application Usability problem WRT WWW: Millions of users with different skills, knowledge, experience and expectations International & multicultural make-up of users & websites Billions of websites Tens of thousands of page designers & authors with […]

Designing for accessibility

Compliant websites do not have to be dull. Do not rely on colour to convey information. Text colour should contrast background colour. Font size defined in CSS should be customisable by user. Important images should have a meaningful ‘alt’ attribute & description. Provide text-based alternative to audio or video content. Content requiring specific plug-in should be available in HTML too. […]


There are several resources regarding accessibility guidelines, including: W3C: Web Content Accessibility Guidelines 1.0 14 guidelines with checkpoints available at Full checklist available at WCAG 2.0 (draft) available at More guidelines available at

The Need to Design for Accessibility/Usability

Web accessibility –  “people with disabilities can perceive, understand, navigate and interact with the Web, and that they can contribute to the Web”. W3C provide guidelines through Web Accessibility Initiative (WIA). Disability Discrimination Act 1995 (DDA) – UK law – accessibility issues. Organisation can be subject to serious legal liabilities for contravening law. DDA part III – unlawful for service provider […]