1. Human Computer Interaction Lecture 08 Interaction Paradigms

2. What are Paradigms
New computing technologies arrive, creating a new perception of the human—computer relationship, giving rise to new paradigm shifts
We can trace some of these shifts in the history of interactive technologies.
History of interactive system design provides paradigms for usable designs

3. The Initial paradigm
Batch processing
Impersonal computing

4. Example Paradigm Shifts
Batch processing
Time-sharing
Interactive computing

5. Example Paradigm Shifts
Batch processing
Timesharing
Networking
@#$% !
???
Community computing

6. Example Paradigm Shifts
Batch processing
Timesharing
Networking
Graphical displays
Move this file here,
and copy this to there.
C…P… filename
dot star… or was
it R…M?
% foo.bar
ABORT
dumby!!!
Direct manipulation

7. Example Paradigm Shifts
Batch processing
Timesharing
Networking
Graphical display
Microprocessor
Personal computing

8. Example Paradigm Shifts
Batch processing
Timesharing
Networking
Graphical display
Microprocessor
WWW
Global information

9. Example Paradigm Shifts
Batch processing
Timesharing
Networking
Graphical display
Microprocessor
WWW
Ubiquitous Computing
Computing everywhere

10. Time-Sharing 1940s and 1950s – explosive technological growth
1960s – need to channel the power
J.C.R. Licklider at ARPA financed several research centres in this regard
Consequences of these research efforts include the concept of time sharing
single computer supporting multiple users
True human-computer interaction was possible

11. Video Display Units More suitable medium than paper or punch cards
First used in military applications
1962 – Sutherland's Sketchpad
By changing something on the display screen, it was possible, via sketchpad, to change something in the computer’s memory.
computers for visualizing and manipulating data
Different representations of same data was possible
Computer was made to speak a more human language, rather human being forced to speak more like a computer

12. Programming toolkits 1968 NLS/Augment system demonstration
Engelbart adopted a new method to develop very powerful interactive system with relatively impoverished technology of that time
the right programming toolkit provides building blocks to produce complex interactive systems
The power of programming toolkits is that small, well-understood components can be composed in fixed ways in order to create larger tools.

13. Personal computing Enabling productivity for mass novice users
First demonstration of this in 1970s – Papert's LOGO language for simple graphics programming by children
Based on a model that children could understand
A computer controlled mechanical turtle used for drawing different geometrical shapes

14. Personal computing Alan Kay at Xerox PARC
Future of computing in small, powerful machines dedicated to the individual – the personal computer
He incorporated smalltalk programming environment for personal computing hardware
He also envisioned the Dynabook – the ultimate handheld personal computer

15. Window systems and the WIMP interface
Humans can pursue more than one task at a time
A personal computer which forced the user through all of the tasks needed to achieve some objective from beginning to end without any diversion was not appropriate
To be an effective partner, a PC needs to support multiple threads of activity simultaneously
A computer system needed to present the context of each activity so that user can distinguish them

16. Window systems and the WIMP interface
Solution: Separate the physical presentation of different logical threads on display device
The window is the mechanism for these physically and logically separate display spaces
windows, icons, menus and pointers now familiar interaction mechanisms
First appeared in 1981 –
Xerox Star first commercial
windowing system

17. Metaphor
Relating computing to other real-world activity is effective teaching technique
LOGO's turtle dragging its tail
file management on an office desktop (First time used by Xerox Alto and Star)
financial analysis on spreadsheets
Keyboard use in word processor as a typewriter
virtual reality – user inside the metaphor
Problems
some tasks do not fit into a given metaphor
Scanning a file for viruses
cultural bias
It should not be assumed that a metaphor will apply across national boundaries

18. Direct Manipulation
Designers noted that their products were gaining popularity as their visual content increased
1982 – Shneiderman coined this phrase. He described
visibility of objects
incremental action and rapid feedback
syntactic correctness of all actions
replace complex command languages with direct actions (hence the term “direct” manipulation)
In 1984 – First Macintosh personal computer demonstrated the inherent usability of direct manipulation.

19. Direct Manipulation
Direct manipulation for the desktop metaphor requires files and folders to be made visible representing underlying files and directories
The model-world metaphor
What You See Is What You Get (WYSIWYG)

20. Multimodality
Mode: a mode is a human communication channel e.g. Visual, audio or haptic (touch)
Multimodality means simultaneous use of multiple channels for input and output
A multi-modal interactive system is that which relies on the use of multiple human communication channels.
We can say that all interactive systems are multimodal because all use at least two human channels i.e. Visual and hepatic

21. Computer Supported Cooperative Work (CSCW)
CSCW is collaboration of individuals via computer
Emerged with the advent of strong computer networks
CSCW removes bias of single user / single computer system

22. Computer Supported Cooperative Work (CSCW)
Can no longer neglect the social aspects
Electronic mail is most prominent success
A metaphor of conventional mail system
An example of asynchronous CSCW system
CSCW systems built to support users working in groups are referred to as groupware (Ch 19)

23. The World Wide Web
Internet is simply a collection of computers linked together.
Hypertext, as originally realized, was a closed system
Simple, universal protocols (e.g. HTTP), mark-up languages (e.g. HTML) and global naming scheme (URLs) made publishing and accessing easy conceive
First envisioned by Tim Berners-Lee.
First text based browser in 1991
Several graphical browsers in 1993(Mosaic)

24. Agent-based Interfaces
People who work on someone’s behalf e.g. estate agents, travel agents, secret agents etc.
Software agents?
Software which act on behalf of users within electronic world e.g. web crawlers which search the WWW for documents that user might find interesting, spam filtering
Some agents use artificial intelligence techniques to learn, called intelligent agents.
E.g. Eager(performs repeated actions for the user)
Even some intelligent agents are there that don’t have a clear embodiment
Summing function of a Spreadsheet

25. “The most profound technologies are those that disappear.”
Ubiquitous Computing
Based on the idea of moving human-computer interaction away from the desktop and out into out everyday lives.
“The most profound technologies are those that disappear.”
Mark Weiser, 1991
Also called pervasive computing
Late 1980’s: computer was very apparent
How to make it disappear?
Shrink and embed/distribute it in the physical world
Design interactions that don’t demand our intention

26. Sensor-based and Context-aware Interaction
Embedment of computation even deeper, but unobtrusively, in our day-to-day life.
The user is totally unaware of the interaction taking place.
Information is gathered from sensors in Environment
Examples: Washbasin, automatic doors, lights turned on automatically
This information can be used to modify explicit interfaces, do things in background etc.

27. Sensor-based and Context-aware Interaction
Automatic sensing is an imperfect activity. So actions from these ‘intelligent predictions’ should be made with caution.
There are two principles of appropriate intelligence
Be right as often as possible, and useful when acting on these predictions
Do not cause extravagant problems in the event of an action resulting from a wrong prediction
The failure of must intelligent systems in past resulted from following the first principle, but not the second.