Cognition is an important factor when designing effective Interactive systems. Based on the factors below, discuss this statement in relation ton one or all of the factors.Attention; Working memory; Long and Short term memoryThe format of this essay is constructed in such a way as to break down each cognitive factor that I have concentrated on in relation to interactive design. They are namely Long and short term memory and perception. Each factor is defined and then placed in relation to the given question. The overall body takes on the steps of designing interactive systems and shows how problems are over come using cognition.Cognitive science is the interdisciplinary study of mind and intelligence, embracing philosophy, psychology, artificial intelligence, neuroscience, linguistics, and anthropology. Its intellectual origins are in the mid-1950s when researchers in several fields began to develop theories of mind based on complex representations and computational procedures.
Its organizational origins are in the mid-1970s when the Cognitive Science Society was formed and the journal Cognitive Science began. The study of cognition focuses upon two different phenomena: short and long term memory. Short-term memory has a relatively low capacity. How much will be detailed in a moment.
It is fast, if we have something on our mind then we can talk about it almost instantly: what does the letter HCI stand for example. Short-term memory also has a relatively short retention period. This is because we actually have to work to keep items in it. According to Stillings, N., et al.
, (1995). Cognitive Science. Second edition, long term memory, in contrast, has a relatively high capacity. As its name suggests it can store information over a much longer period of time. Access is much slower. Clearly from the previous observations, cognitive processes can be used to design interfaces that make efficient use of short-term memory.
Through such cognitive factors Interactive designers can determine for example that a large number of every day users can only be required to remember a few items of information, hence they should not be forced to trawl back through repetitive and distant memories of training programs in order to operate the system. In fact according to Addison Wesley, Human Computer Interaction, the use of cognition led to an increasingly common trick in user interface design, which is to support short term memory by representing additional information on the display or on index cards. This is effectively what a menu does: it provides fast access to a list of commands that do not have to be memories. In contrast, Johnson-Laird, P., (1988) The Computer and the Mind, states that help facilities are regarded, in terms of cognitive design, as a more long-term memory process. We have to load them and trawl through them to find the information that we need. He also states an important example, seven is often regarded as the ‘magic number’ in HCI. We can see this all around us.
Important information is kept within the seven-item boundary. For instance, postcodes have up to seven components G12 8QT etc. In some cases, it is necessary to break this rule. In these circumstances, the information is broken up into components with less than seven items. In the United Kingdom, phone number are usually divided in this way, (0141) 339 8855.
It follows that users will have difficulty in remembering the contents of menus with over ten items. Command languages with many different options will need additional visual cues if operators are to learn them. Why is seven the magic number? It is as easy for users to hold seven words in short-term memory as it is for them to hold seven unrelated items. Additional information can be held but only if users employ techniques such as chunking. This involves the grouping of information into meaningful sections. It can also involve the use of mnemonics and acronyms to prompt the user to recall additional detail. All of this involves work on the user’s part.
This can jeopardise the success of a user interface. As mentioned, it takes effort to hold things in short-term memory. We all experience a sense of relief when it is freed up. For example, you may have felt this when you finished reciting the remembered items in the previous exercise. As a result of the strain of maintaining short-term memory, users often hurry to finish some tasks. They want to experience the sense of when they achieve their objective, this is called closure: This haste can lead to error.
The early cash dispensers suffered from this problem. Users experienced a sense of closure when they satisfied their objective of withdrawing money. They then walked away and left their cards in the machine. As a result cash will now not be dispensed until you take your card.
An important aim for user interface design is to reduce the load on short-term memory. This can be done through cognition by recording information ‘in world’ not ‘in the head’. This involves the use of prompts on the display and the provision of paper documentation.
Hence the supplementation enables users to navigate their way correctly, hence the effectiveness of cognition.Perception involves the use of our senses to detect information. We have to make sure that people can see or hear displays if they are to use them. In some environments this causes huge problems. For instance, most aircraft produce over 15 audible warnings. It is relatively easy to confuse them under stress.
Background noise can be over 100db. Although such observations may be worrying for the business traveller, what significance do they have for more general interactive design? Von Eckardt, B. (1993). What is Cognitive Science, argues that we must ensure that signals are redundant.
If we display critical information by small changes to the screen then many people will not detect the change. If you rely upon audio signals to inform users about critical events then you exclude deaf consumers. You may irritate users in large offices and baffle users who have the sound turned down.Bibliography: