Electronic encyclopedias are perhaps the most consulted type of application by students and teachers when they are trying to investigate a theme of interest or trying to ascertain a quick answer to a question of historic, scientific, or social value. Encyclopedias provide access to an organized body of information by means of key words, descriptors, sort keys, and expressions. The man-machine interface of encyclopedias is usually intuitive. The results can utilize manifold registries with textual, graphic, sound, multimedia information as well as connections to documents, web sites and other programs. The following list illustrates the type of digital repositories and encyclopedias that could help students or faculty keep abreast of topics of interest.
APOD—Astronomy Picture of the Day—is a free site that daily presents a distinct image of the universe with explanatory comments and links to other sites where further information can be found about what is being observed. It includes links to all daily photographs from June 16, 1995. There are websites that reproduce this collection in distinct languages.
EET - The Encyclopedia of Educational Technology includes a multimedia collection of short articles on instructional design, education and entertainment. It is free.
ENCICLONET provides free access to articles about distinct branches of knowledge. It requires registration.
MEDLINE includes articles about illnesses, examinations, symptoms, lesions and surgical procedures. It contains an extensive collection of medical photographs and illustrations.
MSN ENCARTA has information articles, atlases and games. It requires a paid subscription.
WEBOPEDIA is a dictionary and search engine specializing in concepts related to computers and the Internet. It is free.
WIKIPEDIA is a free encyclopedia that is constructed collaboratively and allows content editing by any user with a web browser.It is interesting to note that some encyclopedias receive contributions (biographies, research summaries, other) which means that they are more than repositories and providers of reference information—they are also receivers.