Human-Computer Interaction & web design
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| Structure of human memory Our minds have a tendency to flush short-term memory in order to get on with the next job. Early automatic teller machines (ATMs) gave the customer money before returning their bankcard. On receiving the money the customer would reach closure and hence often forget to take the card. Modern ATMs return the card first! Class discussion How you think the physical human limitation will impact the interactive system design? COMPUTER Computer system A computer system comprises various elements, each of which affects the user of the system. Input devices Input devices for interactive use, allowing text entry, drawing and selection from the screen. Text Entry ▪ Traditional keyboard (alphanumeric, QWERTY, DVORAK, Chord Phone text entry (T, Phone pad Handwriting and speech recognition Positioning, pointing and drawing The mouse The touchpad ▪ Trackball , joystick Touch sensitive screen, stylus and light pen Output devices Display devices Digital paper VR and D interaction Physical controls, sensors and special devices Printing and scanning Memory Short term memory (STM) – RAM Long term memory (LTM) - Discs INTERACTION Interaction Interaction defines the communication between user and system. It translates between what users want and how system delivers it. It consists of : Interaction models – translation between user and system Ergonomics – physical characteristics of interaction Interaction style – the nature of user/system dialog Context – social, organizational and motivational Interaction models User establish the goal Forming the intention Specifies the actions sequence Executes the action Perceive system state Interprets system state Evaluate system state with respect to goal. Donald Norman’s execution-evaluation cycle (seven stages) system evaluation execution goal Identify why some interface cause problems ■ Gulf of executions – it is the difference between the user’s formulation of actions to reach the goal and the actions allowed by the system. If the systems allows the corresponding actions , the interaction is effective. Goal is to reduce the gulf Gulf of evaluation – is the distance between the physical presentation of the system state and expectation set by the user. If the user is can readily evaluate the presentation in terms of goal, the gulf of evaluation is small. The more effort is required on the part of user to interpret, the less effective the interaction. Donald Norman’s execution-evaluation cycle (seven stages) Human Error – slips and mistakes Slip – Correct formulation of action, user understand system and goal , however action was incorrect. Mistake – goal is not correct. Fix? – Better design (slips, better understanding of the system (mistakes) Abowd & Bale interaction framework There are four main translations involved in the interaction articulation, performance, presentation and observation. each has its own unique language interaction translation between languages problems in interaction = problems in translation “A simple example of programming a VCR from a remote control shows that all four translations in the Download 1.72 Mb. Share with your friends:
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