System User
Individual user, a group of users working together or a sequence of user in organization each dealing with some part of the task or process.
Hint: Users are limited in their capacity to process information
In order to design, it is important to understand the capabilities and limitations of those we are designing for.
HUMAN FACTORS-PHYSIOLOGY
Physical make – up, capabilities
Eg. Keyboard keys cannot be smaller than finger size
Left or right handed?
Movement
Disabilities
HUMAN FACTORS-COGNITION
What goes in our heads when we carry out our everyday activities
Thinking, reasoning, problem solving, memory
The HCI objective is to understand the interaction between humans and computers in terms of how knowledge is transmitted between the two
Attention
Process of selecting things to concentrate on at a point in time
Depends on:
Our goals
If we know exactly what we want to find out, we try to match this with the information that is available
Information presentation
Greatly influence how easy or difficult it is to appropriate pieces of information
Try to read the paragraph below…
According to a rscheearch at Cmabrigde Uinervtisy, it deosn't mttaer in waht oredr the ltteers in a wrod are, the olny iprmoetnt tihng is taht the frist and lsat ltteer be at the rghit pclae. The rset can be a total mses and you can sitll raed it wouthit porbelm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe and the biran fguiers it out aynawy.
Read the lists below, cover it up, and then try to recall as many of the items as possible
3, 12, 6, 20, 15, 49, 81, 76, 8, 97, 13, 56
Cat, house, paper, laugh, people, red, yes, number, shadow, broom, rain, plant, lamp, chocolate, radio, one, coin
T, k, y, w, n, o, c, d, e, q, p, r
According to George Miller’s (1956) theory, 7 ± 2 chunks of information can be held in short – term memory at any time.
How to apply this in interface design?
Design tips…
Have only 7 options on a menu
Display only 7 icons on a menu bar
Place only 7 items on a pull down menu
HUMAN FACTORS-PERCEPTION
How a person perceives what input they get through their senses
Capabilities and limitation of visual processing and understand how we perceive size and depth, brightness and colour
Is the left center circle bigger than the right center circle?
METAPHORS
A conceptual model that has been developed to be similar in some way to the aspects of a physical entity.
Maps elements of the real world on to elements of the system world
Dragging a document icon across the desktop screen was seen as equivalent to picking up a piece of paper in the physical world and moving it.
Benefits of using metaphors
Easier to learn because it is familiar to user
Enables learning by building upon existing knowledge
Provide a powerful way of learning the complexity of a system
A short cut to complete concepts
Disadvantages of metaphor
Breaks the rules
Recycle bin that sits on the desktop
Logically and culturally, it should be placed under the desk
If follow the same rule, user would not be able to see the bin because it would be occluded by the desktop surface
Too constraining
Restricting the kinds of computational tasks that would be useful at the interface
Disadvantages of metaphor
Too constraining
Restricting the kinds of computational tasks that would be useful at the interface
Open a file that is embedded in several hundreds of files in a directory
Inefficient if scanning through 100++ files
Instruct a command to open the desired file by typing in its name
Limits the designer’s imagination
Disadvantages of metaphor
Conflicts with design principles
Not able to understand the system function beyond the metaphor
Overly literal translation of existing bad designs
Virtual calculator which designed to look and behave like a physical calculator
Physical calculator has been poorly designed with excessive use of modes, poor labeling of functions and difficult to manipulate key sequences
STAKEHOLDER
Defined as anyone who is affected by the success and the failure of the system
CATEGORIES OF STAKEHOLDER
Primary
Those who use the system
Secondary
Those who don’t directly use the system but receive the output from it
Someone who receive reports from the system
Tertiary
Those who do not fall into 1 and 2 but who are affected by the success or failure of the system
A director whose profits increase or decrease depending on the success of the system
Facilitating
Those who are involved in designing, developing and maintaining the system
CLASSIFYING STAKEHOLDERS
Classifying stakeholders - An Airline Booking System
“An international airline is considering introducing a new booking system for use by associated travel agents to sell flights directly to the public”
Primary Stakeholders:
Travel Agency staff, airline booking staff
Secondary Stakeholders:
Customers, Airline management
Tertiary Stakeholders:
Competitors, Civil aviation authorities, Airline Shareholders
Facilitating Stakeholders:
Design team, IT Department staff
SUMMARY
We must understand what is the strength and limitation of a user before we start to design any system.
A good system will be able to increase the effectiveness and efficiency of users and is able to accommodate a wide range of user
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