"Heuristic evaluation is an essential element of systems' development".

. The method provides quick and relatively cheap feedback to designers. The results generate good ideas for improving the user interface. The development team will also receive a good estimate of how much the user interface can be improved.

2. There is a general acceptance that the design feedback provided by the method is valid and useful. It can also be obtained early on in the design process, whilst checking conformity to established guidelines helps to promote compatibility with similar systems.

3. It is beneficial to carry out a heuristic evaluation on early prototypes before actual users are brought in to help with further testing.

4. Usability problems found are normally restricted to aspects of the interface that are reasonably easy to demonstrate: use of colours, lay-out and information structuring, consistency of the terminology, consistency of the interaction mechanisms. It is generally agreed that problems found by inspection methods and by performance measures overlap to some degree, although both approaches will find problems not found by the other.

5. The method can seem overly critical as designers may only get feedback on the problematic aspects of the interface as the method is normally not used for the identification of the 'good' aspects.

These benefits clearly outline why heuristic evaluation is considered essential in ascertaining the usability of a system. However, there are definite limitations to the technique. The evaluators of the system are not often representative of the people who will use the system and therefore an evaluation of a system by non-expert evaluators would have limitations in its problem identification, for example, the specialist requirements of an expert system. Ergosoft Laboratories (2001) believe "heuristic evaluation is a good way to identify some problems, but not a good way to prove the absence of problems, prioritize existing problems, or determine the solutions to problems". As these arguments indicate, heuristic evaluation is not a complete evaluation but it does provide an inexpensive and effective way of testing systems.

Both the negative views and positive views of heuristic evaluation help provide arguments as to whether or not such a usability evaluation is essential in systems' development. By looking at Jakob Nielsen's list of ten heuristics in appendix 1 it is possible to deduce that heuristic evaluation is an important part of the development process. With the systems in question being user interaction based, such as websites, usability is vital and heuristic evaluations provide an extremely effective method of detecting potential flaws in the design of a website. A further list of heuristics developed by Constantine (1994) can be found in appendix 2, these further heuristics give a broader outline and further aspects of system testing can be conducted by the evaluators. However, the 10 heuristics by Nielsen provide a level of evaluation which can be conducted by most people not just expert evaluators. The accessibility of this type of evaluation to people who may not be expert users makes heuristic evaluation an important part of all systems development from novice users to experienced users. The evaluation is taken from an analytical viewpoint but based around the needs of the user.

Heuristic evaluation is an essential part of a successful systems' development as it lends a users perspective to programmers design. Without the perspective of the user in the design process a system can very quickly become a website based around a designers preferences. If problems to do with usability are not detected in the design stage then even more minor problems can turn into major problems when users find these problems. A minor problem such as a misspelled link can have major ramifications for the user and the designer.

Other test methods such as Empirical testing, a test with real users, can also help but this does not deliver more analytical results, where as the Heuristic evaluation method allows the evaluator to deliver both. This makes Heuristic Evaluation an essential part of a systems' development.

Bibliography

Trenner et al (2001) The Usability Business: Making the Web Work, Springer-Verlag, London

Hackos & Redish (1998) User and Task Analysis for Interface Design, John Wiley & Sons Publishing, New York

Abowd, G (1994) Human Factors in Software Development

cited at http://www.cc.gatech.edu/computing/classes/cs4753_94_fall/handouts/heur.eval.html

Nielsen, J (2003) Heuristics for User Interface Design

Cited at http://www.useit.com/papers/heuristic/heuristic_list.html

Constantine, L. L. (1994) Collaborative Usability Inspections for Software Software Development '94 Proceedings, Miller Freeman, San Francisco