In the summer of 2003, Ted Clemmedsson designed a 3D world simulation for Higgins. The simulation is used as a controlled test environment for data collection and user studies.
The 3D world simulation is coded in X3D/VRML. The original work consists of a large number of objects that may be found in a city, such as houses, streets, squares, lamp posts, ATMs, etc. The models were originally created in Internet Space Builder, and are encoded in VRML. The objects have been categorised and adapted to fit the domain knowledge encoded in the Higgins domain model, and VRML cities or city sections can be generated directly from the model.
The 3D world simulation and the related protocols and tools are considered to be beta versions.
A square with a fountain in the Kymlinge 3D world simulation
- The 3D world "Kymlinge", which was used in the first Higgins data collection in September 2003, and presented in the experiments section. The world features standard houses, streets and pavements as well as more distinct features sucg as fountains and church towers.
The elusive Kymlinge subway station in 3D world simulation
The 3D world simulation is not a part of the Higgins dialogue system as such, but rather a controlled test environment used to emulate real user situations. There are several reasons for wanting to do this, for example:
- The fact the the environment and the objects it contains is controlled helps judging how well the language components do their job.
- Testing and data collection is considerably cheaper in a controlled lab environment than in the field
- The environment makes it possible to log the subjects' movements and actions in a cheap way
Kymlinge 3D world simulation seen from above
Naturally, there are disadvantages to using a synthetic test environment as well. These would mainly be connected to the fact that we do not know how well our simulation compares to a real world situation. It is clear, however, that there are problems in real world situations that will not be seen in the simulated environment, and it is likely that the simulated environment will introduce certain problems that are not relevant in a real world situation. However, when it comes to the type of research aimed at in the Higgins project, we think the advantages of using a controlled simulated test environment by far outweighs the disadvantages.
The belltower of Kymlinge Church from below
The 3D world simulation is used for exemplifying situations in the Higgins domain, for collection of domain dependent speech data, for testing of modules and solutions, and for demonstrations.
The view from the belltower of Kymlinge Church
At present, the worlds will run in most widespread Web browsers with the required plug-in and as an Perl wrapped ActiveX object under Windows. The wrapped version communicates with other processes using the CTT broker (protocol under development) or by writing to and reading from files. User movements and actions are logged, and can be read and replayed. A web browser version with the same communication protocol is under development, but is not high priority at present.
Copyright © 2002-2004 Jens Edlund, Gabriel Skantze and the members of the Center for Speech Technology
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