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 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

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

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.

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

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

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

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

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.

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)

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

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

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)

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)

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, email 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

“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

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.

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.