Chris Chris - You raise some excellent points, which I'm going to address in succeeding articles. Precision: the steps and results of a task will be what the user wants. In consolation, one or two evaluators are often sufficient in the early stages of development to identify the majority of usability problems. Consistency: different parts of the system have the same style, so that there are no different ways to represent the same information or behavior. Countless pieces of research have shown that usability is important in product choice, but perhaps not as much as users themselves believe; it may be the case that people have come to expect usability in their products 1. Heuristics can be used in two ways: during design, to help you choose among alternative designs; and during heuristic evaluation, to find and justify problems in interfaces.
Error prevention: Even better than good error messages is a careful design which prevents a problem from occurring in the first place. He coined the term 'to satisfice', which denotes the situation where people seek solutions or accept choices or judgments that are 'good enough' for their purposes, but could be optimised Simon 1957; see the encyclopedia entry 'satisfice'. Three classes of input cards are used for this program: a The header card contains any useful information to be printed at the head of each output page. I think that basic concept is all wrong. The evaluators must either record problems themselves or you should record them as they carry out their various tasks to track any problems they encounter.
Typically, a heuristic evaluation session for an individual evaluator lasts one or two hours. In its , the method involves a few literate persons that evaluate a given design in the case of Nielsen's method, a web page on the basis of a set of heuristics. Harlow, England: Pearson Education Limited. So heuristic evaluation is not the same as user testing. Heuristic evaluation can be a useful inspection method; however, some experts have identified issues with evaluators reporting false alarms, rather than genuine problem elements within designs.
In heuristic evaluation, evaluators can supplement sets of general design principles with additional heuristics that match the product category or its characteristics, as necessary. The computational efficiency of the code was found to be high but strongly dependent upon problem attributes. Usability testing has been around since at least the 1980s, but began to be widely practiced about the same time Nielsen and Molich published their heuristic evaluation method. Less than five heuristics might lead to a lack of stringency when identifying potential problems and issues, but on the other hand, more than ten may overburden the evaluator as they must analyze the design with all of these heuristics in mind while the heuristics may also conflict with each other. One possibility for extending the heuristic evaluation method to provide some design advice is to conduct a debriefing session after the last evaluation session.
Figure 3 Curve showing how many times the benefits are greater than the costs for heuristic evaluation of a sample project using the assumptions discussed in the text. Quite often, usability problems that are discovered are categorized—often on a numeric scale—according to their estimated impact on user performance or acceptance. Copies of the program listing are available from the author. Heuristic evaluation may find problems that user testing would miss unless the user testing was extremely expensive and comprehensive. We cited research suggesting a new approach to heuristic resource constrained scheduling algorithms.
Using this formula results in curves very much like that shown in Figure 2, though the exact shape of the curve will vary with the values of the parameters N and l, which again will vary with the characteristics of the project. Unfortunately, this problem belongs to a class of problems where, at this time, optimal solution can be found only for unrealistically small problems of marginal practical value. This makes heuristic evaluation suited for use early in the usability engineering lifecycle. Get your handful of stakeholders to do the same activity too, and then compare the results. ExtPrice and UnitPrice are strange labels match real world 6. These heuristics are general rules that seem to describe common properties of usable interfaces. Longer evaluation sessions might be necessary for larger or very complicated interfaces with a substantial number of dialogue elements, but it would be better to split up the evaluation into several smaller sessions, each concentrating on a part of the interface.
Heuristic evaluation is a usability engineering method for finding usability problems in a user interface design, thereby making them addressable and solvable as part of an iterative design process. Evaluators measure the usability, efficiency, and effectiveness of the interface based on 10 usability heuristics originally defined by Jakob Nielsen in 1994. Even ten experts may only surface 85%. Each square shows whether the evaluator represented by the row found the usability problem represented by the column: The square is black if this is the case and white if the evaluator did not find the problem. This meeting offers a forum for brainstorming possible solutions, focusing on the most severe highest priority usability problems. One way of building a supplementary list of category-specific heuristics is to perform competitive analysis and user testing of existing products in the given category and try to abstract principles to explain the usability problems that are found Dykstra 1993. Heuristic evaluation was codified around 1990, at a time when it was expensive to get access to users.
Nielsen developed the heuristics based on work together with in 1990. It's tough to balance dispensing unsubstantiated advice with putting questions off till you have done your research but it is a compromise that needs to be made and you are going to have to draw on general design principles, your instincts and experience. Otherwise the usability heuristic evaluation will lack user focus and be less effective. For example, an icon that represents one category or concept should not represent a different concept when used on a different screen. Be consistent in everything design elements, microcopy, etc. Flexibility: the design can be adjusted to the needs and behaviour of each particular user.