The terms VR and MUVEs• 3D virtual environments (VEs) simulate real or imaginary environments that give

users the sense of "being there".

• Virtual environments (VEs) first emerged in the '70s and later on, led to MUDs (Multi-user domains) and MOOs (Multi-user domains object-oriented).

• The turn of the century saw the emergence of 3D multi-user VEs (MUVEs). The most popular MUVE is Second Life (SL) which was launched in 2003 (http://secondlife.com/). In SL, the user can create his/her own avatar (virtual self) and explore unique virtual environments. SL soon grasped the educators' attention: social exchange, collaboration between avatars, visual and audio stimuli are but a few of its real-time advantages.

• In 2007, the OpenSimulator project (http://opensimulator.org/) was launched to take a further step: it is an open source MUVEs server, supporting several clients while maintaining compatibility with SL.

• The aforementioned applications are only but two out of a large number of similar or totally different technologies, all trying to exploit the potential of MUVEs.

The terms VR and MUVEs• Constructivism provides the theoretical framework for the educational uses of MUVEs .

• Constructivism supports the notion that learners construct knowledge on the basis of what they already understand and as they make connections between new and old information. Learners' prior ideas, experiences, and knowledge, interplay and may even clash with new experiences and their interpretations of the surrounding environment .

• Inconsistencies between what they already know and new persuasive information bring their current understanding into question and results in cognitive conflict (Bruner 1973). When students resolve these inconsistencies, they actually create new ways to reconcile their prior knowledge with the new information. Thus, the resolution of cognitive conflict drives learning.

• Four are their key features; immersion, interaction, imagination, and interest, which all lead to probably the most longstanding and direct benefit of VR for education, that of motivating learning.

• VEs' significance in education lies in the fact that they enable learners to explore the virtual environment, use and manipulate virtual objects, and so they encourage them to express their personal thoughts and to construct their knowledge.

• Also, the interactions with the virtual objects or with other users, enable students to become active learners. VEs attract the interest of students and, in combination with the in-world activities, the educational process becomes more effective

Basic characteristics

3D graphics

No interface

High interactions

Free exploration

First and third person view

Hardware

Types(M.U.D.’s (Multi-User Dungeons

M.O.O.’s (MUD Object Oriented)

Desktop VR

Semi–immersive/Projected Virtual Reality

Fully–immersive Virtual Reality

Augmented Reality

What type of VR is suitable for education?

Frames per second (FPS)

Hardware concerns

Poly count

Lightning

Textures

Tricks Level of Detail (LOD)

The Open Simulator, OpensimSecond Life is a commercial product with relatively high cost for maintaining a "property". These two characteristics motivated a number of programmers to develop an open source alternative, called Open Simulator or Opensim for short. Although it is still at an early stage (Alpha stage), the platform is fully functional and compatible with Second Life.

Opensim is under constant development from a growing team of programmers and new re-leases come out almost every month. The number of users also rapidly increases though still far from the number of Second Life users. Opensim users can use their own computers as servers and host a virtual world. The only limit of the size of the virtual world is the computer's capabilities.

In summer of 2010 Second Life decided to shut down Teen Grid (the part that was used by teenagers). Later, in autumn of 2010, the pricing policy was changed and there are no more reduced fees for Universities and educational institutes. As a result, many institutes turned to Opensim as an alternative platform.