"[E]nsure that the current state of things is displayed in a coherent and easily interpreted format—ideally graphical." #readingToday
Rule-based mistakes are difficult to avoid and then difficult to detect. Once the situation has been classified, the selection of the appropriate rule is often straightforward. But what if the classification of the situation is wrong? This is difficult to discover because there is usually considerable evidence to support the erroneous classification of the situation and the choice of rule. In complex situations, the problem is too much information: information that both supports the decision and also contradicts it. In the face of time pressures to make a decision, it is difficult to know which evidence to consider, which to reject. People usually decide by taking the current situation and matching it with something that happened earlier. Although human memory is quite good at matching examples from the past with the present situation, this doesn't mean that the matching is accurate or appropriate. The matching is biased by recency, regularity, and uniqueness. Recent events are remembered far better than less recent ones. Frequent events are remembered through their regularities, and unique events are remembered because of their uniqueness. But suppose the current event is different from all that has been experienced before: people are still apt to find some match in memory to use as a guide. The same powers that make us so good at dealing with the common and the unique lead to severe error with novel events. What is a designer to do? Provide as much guidance as possible to ensure that the current state of things is displayed in a coherent and easily interpreted format—ideally graphical.
Design of Everyday Things Revised, Don Norman