Human Factors In Design - Assignment Example

The term human factor is used in many fields of study because of the human involvement in these factors. However the general meaning of human factor is the study of all aspects of human behaviour and how they relate to the surrounding world. This study is aimed at improving performance in operations and safety. As far as technology is concerned, the term human factors may be seen to refer to the study of factors distinct only to human e.g. cognitive properties and social behaviours which influence the working and functioning of technology. In design, the human factors are considered. For example, before one designs, he/she should consider the capabilities and limitations of those that you are designing for. As these considerations are made, one assumption is usually used and that is: that all users share common capabilities. However, it is important to note the fact that there are other individuals with differences which need not be ignored during design. Some of the human factors considered in design include: perception, memory, response time, handedness (left or right), attention, cognition, movement etc. All these are considered before design to ensure that the end product is workable and performs according to plan. This paper seeks to highlight the influence of human memory in the interface design (Carey, 1996: pp.28-32). What aspects of human memory are considered before the interface design How do these considerations increase the quality of interface design These and many more questions shall be answered in this paper. Interface design has often been defined as the enabling of client customer or visitor to interact with a product especially a piece of software. Interface design is sometimes referred to as the User Interface Design or User Interface Engineering which refers to the design of a computers, websites, mobile communication devices, software applications, machines, etc with main focus being on the experience of the user and interaction. The main goal of User Interface design, besides the use of graphics to make products attractive, is to ensure a simple and effective interaction between the user and the product so as the user's objectives, aspirations and expectations are met. For example, the use of bold and highly visible graphics in user interfaces ensures that the work represented by the graphic is accomplished more than one paying unnecessary attention to the graphic itself. In this case, the design pays attention to the human factor called visual cognition or generally, visibility and it takes care of human difference such as short sightedness and this explains the boldness to ensure that those with visual problems are able to see the icon or graphic. However memory can also be used in User interface design as will be seen in the later sections of this paper. Therefore, in User Interface, the mouse, keyboard and the menus of a computer system, makes it easier for the user to communicate with the operating system so as the user can achieve a specific goal e.g. in communicating with the operating system the user is able t/o carry out a given task (Thimbleby, 1990: pp.4-12).It should be noted that user interface design is not limited to computers only. In fact, interface design ranges from computer systems, commercial planes, machines, cars etc. The human memory is rather the part of human beings that has baffled many. Many wonder how it works but the most important part is that the human memory is more of an information processing system. There are three types of human memory: the sensory memory, the short term memory (STM) and the Long term memory (LTM) (Norman, 1982: pp.176-182). To understand the influence of human memory in the interface design process, it is important to understand how the human memory works. The working of the three types of human memory and their interactions is captured in the diagram below: Source: http://www.cc.gatech.edu/classes/cs6751_97_winter/Topics/human-cap/memory.html The sensory memory buffers the Sense-received stimuli and there is a sensory memory for each and every sensory channel. The types of sensory memory can therefore be said to be iconic, echoic and haptic which represent the memory for visual stimuli; memory for aural stimuli and memory for touch respectively. Information is often passed from the sensory memory to the STM through attention and this helps filter stimuli thus only allowing in stimuli that is of interest at one particular time. Short term memory on the other hand can simply be said to be a scratch-pad that is used to temporarily hold and recall the information that is under process. For example, for one to understand the full length sentence, he has to hold the initial parts of the sentence in his STM as he reads the rest of the sentence. This type of human memory is highly volatile (has a span of 200s) and is highly limited in space. Disturbance occurs in the short term memory and it affects it ability to retain information and thus this explains the desire to quickly finish the tasks held in the STM sooner may be before interference sets in to interfere with the retention of information. STM is also called the working memory. LTM stores information for a longer period and hence its name. Very little decay occurs in this kind of human memory and it receives information from the STM. There are two main types of LTM namely: the episodic memory and the semantic memory. Episodic memory is the one which enables one to recall and reconstruct the events that took place in ones life. Semantic memory is a record of the skills, facts and concepts that one has acquired over time and it often derives information from the episodic memory. The processes that take place in the LTM can be classified into three: storage, retrieval and deletion. Rehearsal or repeated exposure to stimuli transfers information from STM to LTM. Deletion can be caused by decay and interference and it constitutes the process of forgetting if at all there is anything like that; do people really forget or it becomes difficult for them to access the information in their LTM Under retrieval, there are two processes i.e. recall and cognition. Recognition is less complex and the presentation of information evokes knowledge that this information has been seen before. Recall on the other hand is more complex than recognition and just a retrieval cue enables one to quickly access information in the LTM (Gregg, 1998: pp. 122-9). Having understood the composition of the human memory, then it is now easy to see how this human knowledge influences interface design. Let us assume that one is set to design a computer software for a school (an environment has more of human memory at play). How is human memory likely to influence this design Sensory memory is built from the following sensory activities: Listening, Making associations, Memorising, Using the keyboard Speaking, Looking etc. therefore the interface should enable dialogue and communication with the learner. This dialogue can be enabled through the use of keyboard in which the learner is able to communicate with the computer. Impact Attention transfers information from the sensory to the short term memory where it is processed and then taken to the LTM. The interface in this design should be able to capture the learner's attention. The learner should be able to focus on one particular event while ignoring others among the mass of competing environmental stimuli. To be able to capture the learner's attention, the use of attractive graphics or icons may provide an immediate visual impact. These graphics can be used to persuade, amuse and motivate the learner if designed carefully. Besides the graphics securing the learner's attention, they also aid in memory and make the learner to stay on the task long enough. The visual impact makes the learner to attend to the visual stimuli thus transferring the information read to the STM for processing before it can finally be stored in the LTM. Apart from graphics that cause visual impact other interface devices which appeal to any of the senses may be used so as to attract and sustain the attention of the learner thus enabling memory and consequently learning (Brown, 1998, pp.86-9). Intuition The interface is the communication means between the user and the computer system and therefore it should be designed such that it makes it easier to be understood and to be used by the learner. Make the interface as consistent as possible because repetition breeds familiarity thus making the learner (user) to use the interface so easily and comfortably without aid of manuals, instructions etc. Further, the interface needs to be made relevant to the learner who is the user in this case. It should be noted that anything that is picked by our senses is information subject to processing by the mind and for this reason make sure that the interface is clear and valid thus avoiding unnecessary clutter that may hinder the easy use of the interface. The best interface is the one which requires the least learning effort (Tay, 1996:pp.23-8). Navigation The navigation buttons should never be the source of distraction. The learner should always pay uninterrupted attention to the content so as to commit the content to memory. Any distraction caused as a result of looking for the navigation buttons may hinder memory. As indicated earlier, the STM is very vulnerable to disturbance which can affect the process of learning. If the information in the STM does not get to the long term memory due to disturbance, then information is lost and retrieval of such information in future is not possible and as such no learning could have taken place. Therefore, the navigation should remain in the same place in every screen of your interface such that the learner soon learns how to quickly find their way around the screen and sites in the interface thus only remaining with the subject matter to contend to. Text When designing the interface for the school software, due attention should be paid to the size and type of the font and the area of the screen used for the text. This helps easy visibility thus easy readability. Easy visibility affects memory as seen earlier because it forms sensory memory which on attention passes the information to the STM before the information can then be passed to the LTM for permanent storage and future retrieval. Substantial effort is required so as to focus attention only to one of the many competing environmental stimuli. The stimulus to which attention is favourably given forms sensory memory information which can then be passed on to the STM and the process continues. Therefore, if the text type and size used makes the learner struggle to read, then uploading the information contained in the text to the sensory memory, STM and finally LTM is going to be absolutely difficult. For this reason, in the design of interface, one should ensure that the text size and type used is that which can be easily readable with minimal effort (Hartson, 1992, p.128). Images The animations, photographs used graphics should be used only with the consideration of the age of the readers (end users). For young children, use more of the graphics because they aid in memory. The graphics used should be funny and attractive to court attention fro the learners. Generally, human mind is more receptive to pictures and graphics than plain text regardless of the age. Based on this fact, then one can confidently say that graphics and pictures enhance memory. Therefore, graphics and pictures should be used more in the design of the interface. Video It is common knowledge that anything learnt through video is likely to be remembered more than that learnt otherwise. Therefore if video is used in the interface design, then make sure that the buttons for its control are available for the learner to easily rewind, pause, forward or stop as need may be so that the learner is able to get most of learning content for processing and subsequent commitment to memory at the learner's own rate. If the video runs fast, the learner may rewind to get the pictures and words clearly so as to get valid sensory information to be processed in the STM. Therefore, the designer should make sure that the video used in the interface has control buttons whose functionality is evident by convention. Colour From research, it has been established that high contrasting colours between the text and its background enhance reading due to good visibility. Therefore, except in situations where graphics and pictures are use, the interface screens should have a maximum of three or four colours. It is scientific knowledge that colours have specific impacts on human feelings and moods. Some colours are relaxing, others exciting and others quite disturbing and sickening. For this reason, the colour of the interface screens need to be the one that the right ambience and mood for learning. High contrast colours enhance visibility and readability and thus improving performance in activities such as recall and retention of information. Emotions can affect learning process and since colours evoke emotions, care needs s to be taken. As stated earlier, emotions can also affect memory and this is why even more care should be taken when choosing the colour to use in the interface screen. Colour is however important for children learning and this explains why most of the children's objects such as dolls, clothes, balls, bicycles etc are colourful. Colour can be highly motivating for children. Colour blindness learners may have problems with specific colour combinations and if such colours are use, then learning and consequently memory is hampered (Mandel, 1997, p.320). Balance Finally, symmetry in the interface screen is necessary to make it pleasing to the eye and thus retain attention. However, if simplicity and clarity are require for the purpose of learning, and then the text should only occupy a reasonable portion of the screen thus making the screen less busy. Grouping of material is also desirable especially for learning purposes Therefore, in conclusion, much care needs to be taken when designing interface. Interface design can never be devoid of human factor consideration because if anything, it is the channel through which the end user communicates with the computer system. Put yourself in the shoes of the end user and if this is not possible, always keep testing it while paying special attention to the responses from those who are engaged in the testing process. Success of any interface design is when it is accepted and embraced fully by the human users and when it fulfils the goals of the user. Therefore, at every stage of the interface human factors applicable to that stage should be considered. Memory, as one of the human factors in design cannot be ignored in the interface design. References Carey, Jane. Human Factors in Information Systems Intellect Books Publishers, 1996, pp.28-32 Thimbleby, Harold. User Interface Design ACM Press, 1990 pp.4-12 D. A. Learning and Memory. New York: W. H. Freeman, 1982. Norman, Gregg, Vernon. Human Memory Taylor & Francis Publishers, 1998, pp. 122-9 Tay, Vaughan. Multimedia: Making it work, Osborne: McGraw-Hill, 1996, pp.23-8 Brown, Marlin. Human-Computer Interface Design Guidelines Intellect Books, 1998, pp.86-9 Hartson, Rex Advances in human-computer interaction Intellect Books, 1992, p.128 Mandel, Theo. The Elements of User Interface Design Wiley & Sons Publishers, 1997, p.320 Read More