Designers often agree a set of criteria (heuristics) for evaluating the usability of an design or interface, and Jakob Nielsen developed his own set of heuristics for evaluating computer software (and have been adapted and updated for mobile phone apps). Although the approach is informal, it is a good way to ensure that a set of best practice “rules of thumb” are used to screen prototypes of products or interfaces before they are given to users to test.
This represents a very disciplined approach to screening and testing potential design against an agreed and consistent set of criteria. TapestryWorks have developed our own general framework for evaluating designs against behavioural criteria that reflect habitual and unconscious behaviours (read more here). We have applied the framework to different contexts such as pricing, market research buyers, designing presentations, and messages and communication strategies.
Jakob Nielsen’s own framework covers:
- visibility of operation (can we see what’s happening)
- correspondence between operations and the real world (see mapping)
- user control and freedom (how easy is it to operate)
- error prevention
- consistency and standards
- recognition rather than recall (see here)
- flexibility and efficiency of use (see flexibility-usability trade off)
- aesthetic and minimalist design (see Ockham’s razor)
- help users recognise, diagnose and recover from errors
- help and documentation
The value of such frameworks is to provide an approach that can be followed by experts and learners alike, based around common criteria that are known to be important to making a usable design. Typically heuristic evaluation is conducted by a team of people who then compare results to come to an overall conclusion and detect design faults and improvement opportunities at an early stage.
Heuristic evaluation employed at an early stage of design with early prototypes can help identify and diagnose potential problems at an early stage and leads to better and more optimised design solutions as a project progresses, simplifying and improving the value of testing in the real world. It is also a great learning tool for design teams, helping to build their expertise in detecting usability problems and improved design solutions.
Universal Methods of Design by Martin & Hanington
Usability Inspection Methods by Jakob Nielsen
“All about the heuristic evaluation” by Paul Olyslager (https://www.paulolyslager.com/about-heuristic-evaluation/)
The Checklist Manifesto by Atul Gawande