Definition

The term 'agent' generally means a representative who acts on behalf of other persons or organizations. When looking at the term in relation to interactivity design, it ('software agent') can be defined as any software that is designed to use intelligence to automatically carry out an assigned task, mainly in retrieving and delivering information for a user or program.

Examples

Spam Filter: are agents that will automatically go through your emails and filter out any spam and store them as junk mail or delete them.
Buyer Agents: or shopping bots, are basically used for helping Internet users find products and services they are searching for. For example, when searching for an item on eBay or Amazon, at the bottom of the page there is a list of similar products that other customers who did the same search looked at.
User Agents: are meant to carry out tasks automatically for the user. For example, some bots sort out emails according to the user's order of preference or fill out web [page forms with the user's stored information (Form Filler Bot).

References

"Agent." Dictionary.com. 2006. 18 January. 2008. http://dictionary.reference.com/browse/agent.
Nwana, Hyacinth. "Software Agents: An Overview." Knowledge Engineering Review, Vol. 11, No 3, pp.1-40, Sept 1996. © Cambridge University Press, 1996. 18 January 2008. http://agents.umbc.edu/introduction/ao/
"Software Agent." Wikipedia. 17 January. 2008. 18 January. 2008. http://en.wikipedia.org/wiki/Software_agent.

last edited: January 18, 2008