HCI s 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 GUI’s • User friendly because you don‘t 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 • GUI’s 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 DialogueAdministrators/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 isn’t on the list of options given or you don’t know which option it is in.

12. Touch sensitive screens • USE POS systems such as at McDonalds. • Adv • Don’t 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 – can’t 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. HCI’s Factors which must be taken into account when designing HCI’s 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 children’s learning program would be colourful ; large text; lots of graphics and sound

16. 2.Who is going to use it? HCI’s 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/signposting/ 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'