2.2.1. Networked Text-based Virtual Worlds
Text-based virtual worlds are real-time multi-person virtual environments created through text descriptions rather than graphics. These environments are commonly known as MUDs, or Multi-User Dungeons, and MOOs (MUD Object Oriented), a MUD where users define spaces and objects. Developed from on-line game environments that allow several participants to play a computer game of Dungeons \& Dragons together, MOO's and MUD's support real-time interactive use among a large number of multiple users that may be sitting at remotely located computers but sharing the same virtual world.
These text-based virtual environments were primarily designed for entertainment, but an increasing number of MUDs and MOOs now exist for education. One of the earlier ones is ExploreNet, a networked virtual world where children interact with each other via avatars in settings filled with computer-controlled props. ExploreNet employs a story-like two-dimensional graphical interface to combine networked use of text and graphics \cite{Hughes96}. The Grassroots project is a popular text-based simulation of a neighborhood in a MOO combined with a WWW page. Students from around the world recreate their neighborhoods and share them with others \cite{Parsons96}. A more ``traditional'' MOO is Moose Crossing, an improved version of the earlier MediaMOO project, designed for kids to program objects and their behaviors \cite{Bruckman95}. A few other MOOs have been developed for teachers, such as Diversity University and Deadalus MOO, but most of them are more loosely defined and function as forums, or ``chat rooms'', where issues of self expression, identity, social interaction, and cultural awareness may be explored.
With respect to education, the advocates of textual VR cite two virtues of text-dependence: the creation of a community context, and the encouragement of reading and writing. The sense of community inspired by these environments allows the exploration of social codes, power and group dynamics. The fact that the world is built through text rather than graphics supports the second argument. Text-based VR has developed a strong connection to narrative and the area of Interactive Fiction (IF), as participants can assume various identities, develop situations cast in story-like or adventure-based formats, and interact with objects and characters.
On the other hand, the lack of a specific learning structure and direction, may leave many participants floundering in the virtual environments without specific goals. As with the Internet, making information available isn't enough to qualify the setting as an educational experience. Additionally, the lack of multi-sensory representation in the physical sense (visual, auditory, and tactile), may render MUDs incomplete learning environments in and of themselves. Moreover, students and teachers have to learn the necessary design and construction conventions to create specific text-based worlds and objects. The detailed mastery of these rules is in many cases difficult and irrelevant to learning.