Human Computer Interaction Lecture 08 Interaction Paradigms

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

The Initial paradigm Batch processing Impersonal computing

Example Paradigm Shifts Batch processing Time-sharing Interactive computing

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

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

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

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

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

Time-Sharing 1940s and 1950s – explosive technological growth 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

Video Display Units More suitable medium than paper or punch cards First used in military applications 1962 – Sutherland's Sketchpad (allow users to draw on a screen with a light pen.) 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

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. NLS system was the first to employ the practical use of hypertext links, the mouse, raster-scan video monitors. 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.

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

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

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