Human Computer Interaction Lecture 09 Interaction Paradigms

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)

Hypertext key to success in managing explosion of information mid 1960s – Nelson describes hypertext as non-linear browsing structure hypermedia and multimedia

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

The World Wide Web Internet is simply a collection of computers linked together. WWW builds on top of it. 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 picture 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 excessive 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.