HCIs Human Computer Interfaces

1
HCIsHuman Computer Interfaces
2
GUIs (Graphical User Interfaces)

• Windows
• to allow multitasking and display file structure
• Icons
• are symbolic representations of files
• Menus
• to list appropriate facilities
• Pointer
• to select and choose the command or facility
• you want.

3
Advantages of GUIs

• User friendly because you dont have to remember
  all commands
• The menus limit the commands available to avoid
  confusing and ambiguous options.
• Can be customised to suit the needs / preferences
  of the user.
• The use of graphical icons provide intuitive,
  easily recognisable shortcuts for the novice user
  e.g. printer icon
• Easy to use with minimum training. Intuitive and
  'user-friendly' method. The mouse corresponds to
  the movement of the pointer on the screen and
  allows an intuitive way of communicating
  commands.
• Suitable for users with lower IT skills. A number
  of different applications will use the same icons
  and methods - so each one 'feels' the same.
• Multitasking. Can run more than one piece of
  software so easy to transfer data between them
  e.g. importing clipart pictures.

4
Disadvantagesof GUIs

• Such environments do take up more RAM and storage
  space on the disc but this has not proved to be
  much of a problem the cost of memory and disc
  storage has become cheaper and machines contain
  bigger hard drives.
• Can make the machine run slower
• GUIs take more time to develop. These increased
  development costs will be passed on to the user.

5
Customising an interface

• Toolbars There are standard toolbars which can be
  shown or hidden. Each of these can be altered by
  adding own macros or removing icons that you do
  not use. E.g. the equation toolbar may never be
  used by some users but mathematicians would use
  it frequently and may wish to add other functions
  to it.
• Menus
• Menus can be pull down or pop up The most
  commonly used commands often only appear on the
  menu to avoid clutter but other greyed out
  command are available upon selection.
• Font
• The default font can be altered e.g. partially
  sighted people might want to have a larger font
  on their menus.
• Templates
• This is an outline document which provides a
  framework for writing e.g. business card,
  leaflet, memo, flier Screen view
• Screen views can be changed to allow the user to
  see more or less of a document. E.g. Print view,
  normal view etc.
• Screen colours
• Screen colours can be altered to meet the needs
  of the users. E.g. users with severe dyslexia
  might find blue writing on a white background
  more conducive. Colour blind people may prefer no
  red or green.

6
Command driven

• The ICT technician would use this
• These are systems like MSDOS which require a
  degree of technical ability and are not user
  friendly. Commands are typed in response to a
  prompt. This is not very user friendly and you
  need to know the commands of the operating system
  in order to perform jobs.

7

• Advantages
• faster and more versatile as a number of
  different 'switches' can be used to moderate the
  command. Better for the technical user as they
  can work faster.
• Takes up less memory
• Disadvantage is that commands need to be known,
  typed and spelled correctly need technical
  experience.

8

• Forms Dialogue Administrators/secretaries might
  use this
• Voice interfaces
• - speech recognition systems
• - natural language interfaces
• - speech synthesis

9
Speech recognition systems

• Use
• Voice control in car navigation systems
• Security systems
• Control systems
• Problems
• Have to train computer to recognise voice which
  takes a long time
• Delays in getting commands recognised
• Adv No typing

10
Natural language interfaces

• USE
• Giving instruction / asking question such as in
  expert systems
• Problems  
• users may speak different languages 
• local accents may not be recognised
• some words sound the same - two, to, too there,
  their, whether, weather
• punctuation has to be said e.g. user must say
  comma which is not a natural way of talking.
• Use of sound makes high demands on memory and
  processor speed
• Adv No typing

11
Speech synthesis

• This is the computer speaking to the user
  
• USE
• Giving out telephone numbers or telephone
• selection systems.
• In car navigation systems
• Problems
• The sound is very flat
• Users complain of confusion and a lack of
  personal contact if your enquiry isnt on the
  list of options given or you dont know which
  option it is in.

12

• Touch sensitive screens
• USE
• POS systems such as at McDonalds.
• Adv
• Dont have to remember prices
• no typing so more accurate
• USE
• Public information system such
  as in
• museums
• ADV
• No need for a mouse or keyboard which could get
  stolen or broken easily
• Disabled use overcomes difficulties with
  spelling/dyslexia

13

• Biometric devices such as iris recognition, hand
  prints and fingerprint recognition.
• Use
• Retina scan/iris recognition to gain access to
  room, thumbprints to take out a library book
• Adv
• Individual / difficult to copy
• Accuracy cant get someone else to scan in for
  you
• Can lose smart cards

14

• Dedicated keys
• Soft keys Some keyboards may have programmable
  'function' keys.
• Pointing devices
• OCR Handwriting.
• Graphical devices such as graphics pads used in
  CAD by architects who want to draw on the screen
  as though drawing on paper.
• Game playing devices such as joysticks ,steering
  wheels, game pads

15
HCIs Factors which must be taken into account
when designing HCIs

• 1. Task What is the program designed to do?
• Layout appropriate to task.
• There should be standard feel to software
  which builds up user confidence. Use of colour
  friendliness will put the user at ease but take
  up a lot of RAM as would use of graphical images
• Example 1 A business program would reflect the
  ethos of the business business colours, muted
  colours, business like graphics, minimum clutters
• Example 2 A childrens learning program would be
  colourful large text lots of graphics and sound

16
2.Who is going to use it? HCIs need to
differentiate between non technical and
technical users. e.g. An expert user would
require command line interfaces and hotkeys
i.e. short cut to commands because it is
faster A non technical user would probably
require a graphical user interface which is more
intuitive and uses Windows Icons Menus Pointers
17

• 3. Consistency of layout and navigation/signpostin
  g/ pop up information techniques.
• Navigation around the program should be clear
  consistent and easy to follow
• Example every Next should be in the same place
  using the same icon. Pop up menus must be in the
  same position and have the same format.
  Hyperlinks could all be in a frame to the right
  on every web page

18

• 4. Online and Offline Help
• Example
• On screen help
• Customised user environments-favourites/background
  /wallpapers
• On screen assistants
• Tutorials
• Help and error messages
• Many systems can restrict the level of help
  screen available. A good help system is important
  for the new user and may provide a complete
  online tutorial or online manual or menus
  activated by help keys.
• Error messages or diagnostics are useful to all
  users.
• They must give some indication of the type of
  error that has
• Occurred not simply say 'error'