Revision Lesson 1

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3.3.2 Designing computer-based information
systems

• Revision Lesson 1

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This presentation covers

• Processing Systems
• Designing the user interface

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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.

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Mode of operation

• The mode of operation is essentially how
  processing is carried out.
• When data is processed in groups, it is referred
  to as batch processing.
• When data is processed one item at a time and
  requires user responses, it is referred to as
  interactive processing.
• When data is processed immediately after being
  input, it is referred to as real-time processing.

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Batch Processing

• Processed when the system is not busy (usually at
  night).
• This means that there is usually a delay between
  the data being input into the system and the data
  being processed.
• There is no need for user interaction meaning it
  is not necessary to have a GUI. A command line
  interface will suffice.
• Usually used for processing monthly bills.

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Interactive Processing

• iEach transaction is completed before moving onto
  the next.
• Dependant on response and action from the user.
• GUI is necessary for user to interact with the
  system.
• Used in ATMs, EPOS and ticket booking.

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Real-Time Processing

• The data is processed as soon as the processor
  receives it.
• The data is processed within seconds of being
  input (usually no more than 4 seconds).
• There is sometimes a GUI but the systems often
  run automatically because of the high data input
  rate (usually recorded via sensors).
• Used in transport
• (cars traction control and stability control)
• (aeroplanes autopilot)

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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

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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.

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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.

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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.

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Design principles
Quantity of information
Font
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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.

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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.

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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.

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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.

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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)

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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 UIs are graphical (GUIs).
• They make use of
• Prompts
• Input styles and methods
• Feedback

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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.

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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.

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Method of input

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

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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.

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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.

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Taking the user into account

• You need to be able to explain how a potential
  users
• 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.

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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

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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 users attention
• Keeping menus consistent so they are easily used
  and understood
• Keeping icon symbols consistent too Floppy Disk
  for save icon

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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.

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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!