© NCC Education Limited V1.0 Introduction to Computing  Unit 4: Human-Computer Interaction

© NCC Education Limited V1.0 Human-Computer Interaction Unit Summary of Lecture Examples of human-computer interfaces Human-computer interfaces GUIs Standardisation Speech recognition Natural language recognition

© NCC Education Limited V1.0 Human-Computer Interaction Unit Interfaces  What is the human-computer interface? It is the meeting point of a computer and its human user. It involves: -software -hardware -the computer itself -peripherals -electronic devices

© NCC Education Limited V1.0 Human-Computer Interaction Unit Interfaces Text Graphics Sounds Keyboard Mouse or alternative Touch Screen Microphone Screen Loudspeaker A variety of other components An interface can consist of:

© NCC Education Limited V1.0 Human-Computer Interaction Unit Interfaces An interface affects usability -Usability is the amount of effort that a user has to expend in order to achieve a desired outcome Interfaces should be intuitive They may make use of metaphors -e.g. a desktop Related commands are grouped together Alternative ways of issuing a command Not too much information on one screen Careful choice of fonts and colours

© NCC Education Limited V1.0 Human-Computer Interaction Unit Bad Interfaces  How to drive users mad: slow not standard too much work use abbreviations use technical language hide important functionality don’t talk to users set bad defaults keep them guessing

© NCC Education Limited V1.0 Human-Computer Interaction Unit Patch cables GUIBrowsers Voice ? CLI Punched cards Interfaces Interfaces affect how easy a system is to use They have changed a lot since computers were first invented They are still evolving rapidly

© NCC Education Limited V1.0 Human-Computer Interaction Unit Interfaces  In the beginning.... Jobs and data were input in batches There was little human-computer interaction In the late sixties, commands could be typed In 1981, came the first graphical interface This later became operable by touch New methods are being introduced all the time

© NCC Education Limited V1.0 Human-Computer Interaction Unit Batch Interfaces Data collected together Output collected when finished No interaction with human during processing

© NCC Education Limited V1.0 Human-Computer Interaction Unit Command Line Interface (CLI) Became popular in the sixties Allows commands to be typed Computer outputs text -e.g. MSDOS, Unix, Linux, Bash Still popular today Allows commonly used commands to be batched -this automates processes Requires commands to be learned

© NCC Education Limited V1.0 Human-Computer Interaction Unit #!/bin/bash HELLO=Hello function hello { local HELLO=World echo $HELLO } echo $HELLO hello echo $HELLO MSDOS BASH BASH stands for Bourne Again Shell. (Named after Stephen Bourne who wrote a shell for Unix in the late seventies). A shell is a way of communicating with the operating system kernel. Command Line Interface (CLI)

© NCC Education Limited V1.0 Human-Computer Interaction Unit Menu Driven Interface User is presented with a list of options Options often lead to sub-options Easier to use than command line But can become complex and difficult to navigate Works best with small number of levels

© NCC Education Limited V1.0 Human-Computer Interaction Unit Menu Driven Interface

© NCC Education Limited V1.0 Human-Computer Interaction Unit Graphical User Interface (GUI)  Inputs keyboard mouse  Outputs graphical display

© NCC Education Limited V1.0 Human-Computer Interaction Unit Menus Graphical User Interface (GUI)

© NCC Education Limited V1.0 Human-Computer Interaction Unit Graphical User Interface (GUI)  Drop down menus  Pop up menus

© NCC Education Limited V1.0 Human-Computer Interaction Unit Graphical User Interface (GUI)  Dialogue Boxes set a number of parameters then confirm (or reject) all

© NCC Education Limited V1.0 Human-Computer Interaction Unit Icons Icons are pictures that represent files and processes Graphical User Interface (GUI)

© NCC Education Limited V1.0 Human-Computer Interaction Unit Graphical User Interface (GUI)  e.g. Windows ®

© NCC Education Limited V1.0 Human-Computer Interaction Unit  Windows Graphical User Interface (GUI)  Many applications open on screen at the same time

© NCC Education Limited V1.0 Human-Computer Interaction Unit Skins the same application can take on different looks, sometimes with different functionality 4 different skins for Windows media player Customising The Interface

© NCC Education Limited V1.0 Human-Computer Interaction Unit Web Based Interfaces Wide variety of responses Web page updated Multimedia Interaction through a Web browser Can run applications Can collect data

© NCC Education Limited V1.0 Human-Computer Interaction Unit Web Based Interfaces There are few standards Some conventions are common Text as an alternative to graphics for links Keep clutter to a minimum Small number of choices per screen Readability

© NCC Education Limited V1.0 Human-Computer Interaction Unit Tactile Interfaces Touch screens -Checkouts -Public information systems -Public utilities -Bank transactions -Airport check-in -Train ticket sales Wii (Nintendo) -Body movements can be used for input Simulators

© NCC Education Limited V1.0 Human-Computer Interaction Unit New Ideas About Interfaces Nowadays, we are bombarded with information from many devices. -Cell phones, MP3 players, Blackberries, PDAs, PCs Systems have been developed that pay attention to us. They then only give us information when we are ready. -Eye contact sensors use computer vision to track when a person looks at a device -Attentive messaging systems (AMS) forward s to the device currently in use -Eye proxy, a pair of robotic eyes with embedded eye contact sensors allow a computer to look back at the user, to visually communicate its attention

© NCC Education Limited V1.0 Human-Computer Interaction Unit Standards Accepted norms Allow interoperability Promote easier learning Types: -industry -proprietary -open -de facto

© NCC Education Limited V1.0 Human-Computer Interaction Unit Standardisation Most desktop interfaces are now similar. Common functions are grouped similarly. This helps in learning new applications. It also saves programming effort. Many aspects of an application are taken from operating system libraries. Code re-used. DLLs make this easier.

© NCC Education Limited V1.0 Human-Computer Interaction Unit Speech Recognition Accept voice commands as input Can take dictation to produce a document Can require extensive training of the software Needs to get to know user's voice Very difficult to implement successfully -accents -words with same sounds but different meanings -names

© NCC Education Limited V1.0 Human-Computer Interaction Unit Speech Recognition  Voice output Choice of voices Sat nav Visual disabilities  Voice input Pilot cockpit commands -background noise problems Operating computer when injured Dictation

© NCC Education Limited V1.0 Human-Computer Interaction Unit Natural Language Use ordinary language No need to know strict computer syntax Computer has to extract essential meaning Used in search engines Other web pages Need to analyse sentences to extract their essential meaning

© NCC Education Limited V1.0 Human-Computer Interaction Unit Unit 4 Any questions?