Revision Lesson : DESIGNING COMPUTER-BASED INFORMATION SYSTEMS

THIS PRESENTATION COVERS: Processing Systems Designing the user interface

PROCESSING SYSTEMS For the exam you need to know about: Mode of operation (Discuss processing, response time and user interface) Batch, Interactive and Real-Time processing systems. Operating systems (Describe characteristics) Single user, Multi-user, Multi-tasking, Interactive, Real-time, Batch processing and Distributed processing.

MODE OF OPERATION

BATCH PROCESSING

INTERACTIVE PROCESSING

REAL-TIME PROCESSING

OPERATING SYSTEMS Single-user One user at a time Users must log off before another can use it Multi-user Allows more than one user at a time Usually runs over a network OS manages each user to ensure conflicts do no occur

OPERATING SYSTEMS Multi-tasking Allows the processor to ‘apparently’ deal with multiple processes at the same time. Actually allocates chunks of time to different processing requires and flicks between them. Interactive Requires direct user interaction whilst running. Real-time Usually embedded in another application and can run on their own with no user interaction, but might react to a stimulus caused by the user. For example, the ECU of a car.

OPERATING SYSTEMS Batch processing Given a set of tasks to complete without user interaction. Processes jobs when system is not in use or just before the processed data is required. Distributed processing Computers connected together sharing the work load. Each computer processes parts of the job. Results are later combined.

USER INTERFACES (BASICS) For the exam you need to know about: Design Principles (Discuss design principles) Colour, layout, quantity of information, complexity of language and type of controls. Method of controls (Discuss methods for communication techniques) Computer to person, Person to computer and computer to computer.

Quantity of information Font ColourLayout Complexity of language Controls HCI DESIGN PRINCIPLES

COLOUR Things to think about: Do end users have any disabilities? Colour blindness Dyslexia Colours can trigger reactions (Green is ok, Red is bad) and grab attention. Limit the number of colours (4 per screen, 7 per sequence). Colours can be used to code information.

LAYOUT Things to think about: Consistent layout (between screens and applications). Layout of information and data entry should be logical. Important information and action points need to be in a prominent position. Designing for easy learning and efficient use.

FONT Things to think about: Easy to read. Who are the end users and what are their needs. What equipment will be used and possible ergonomics should be considered. PC, Laptop and hand-held devices are all placed at different distances from the end user. Styles should be applied appropriately for easy transfer of information.

COMPLEXITY OF LANGUAGE Things to think about: Who are the end-users? Complexity kept as low as possible. All errors should be in the simplest of forms. Help should be useful, not condescending. All technical language should be minimal and fit for purpose.

TYPES OF CONTROL Things to think about: Ease of use: Macros:Automate complex or repetitive tasks. Buttons:Navigation or activate macros. Forms:Assist in data entry (logical, validation and verification) Menus.Allows actions to be selected (can hide inappropriate actions)

METHODS OF DIALOGUE You need to be able to discuss methods of dialogue between a computer and a person, a person and a computer and a computer to another computer. They main ways that computers and humans communicate is via a user interface. Modern UI’s are graphical (GUIs). They make use of: Prompts Input styles and methods Feedback

PROMPTS Prompts indicate something to the user. In a command line interface the prompt will indicate that a command needs to be entered. In a GUI, icons are used to prompt the user. Menus are also used to prompt the user to select certain actions.

NATURE OF INPUT This describes how the input will be requested: Question based Form based The next response could be determined by the last input.

METHOD OF INPUT Usually input methods include keyboard and mouse. Touch screens and audio inputs are also becoming more popular.

FEEDBACK Providing limited number of responses to select from. Can be in the form of: Menus and Sub-Menus. Very specific options being available to control what the user can select.

FEEDBACK Providing limited number of responses to select from. Can be in the form of: Menus and Sub-Menus. Very specific options being available to control what the user can select.

TAKING THE USER INTO ACCOUNT You need to be able to explain how a potential user’s: Perception Attention Memory Learning can be taken into account when designing an interface. The presentation on my website goes into a lot of detail about different things to consider...but they all inter-relate with each other.

PERCEPTION Users perceive inputs from sights and sounds. Users have preconceived ideas about how things should be done. Red text = Bad Siren = Bad Ding = Good BONG = Bad

ATTENTION Most people have a limited attention span. Designers need to think about how to increase the attention span of user: Uncluttered screens Easy to access information Clearly labelled input areas Pop up messages, flashing images and sounds can draw the user’s attention Keeping menus consistent so they are easily used and understood Keeping icon symbols consistent too – Floppy Disk for save icon

MEMORY Keeping GUIs consistent with already made GUIs helps to shorten the learning curve. Users make use of pre-existing memory experiences to help them learn. Consistency aids in the recall of actions. It is also important as people have preconceptions about how things should work based on prior experiences.

LEARNING Must look at previous user experience. New interfaces should try and match old system as far as possible. On-screen help is really important. Important to think about perception, attention and memory!