Joze Rugelj

J. Stefan Institute
Ljubljana, Slovenia

Problem based learning is an instructional procedure that, in contrast to conventional education, transfers control over the learning process from the teacher to the students [Schm93]. Students are encouraged to formulate and then follow their own learning objectives and to select the learning resources that best suit their information needs. The role of teachers is mainly in providing advice and suggestions for further work.

Collaborative learning is a key part of the Problem Based Learning approach. A small group of students that meets weekly or even more frequently is faced with a problem to be solved. As students articulate and reflect upon their knowledge, learning and transfer are facilitated. PBL supports development of scientific understanding through real-world cases, development of reasoning strategies and development of self-directed and life-long learning strategies.

In most of the traditional educational settings organization of work in the above mentioned working group is not an easy task due to various reasons. The problem is even worse in some specific cases, e.g. in enterprises where they are looking for an efficient way to organize various forms of life-long learning and training for their employees. Limited amount of time for group work and complicated scheduling procedures for the arrangement of meetings might prevent organizers of training and education from introducing effective innovative approaches.

For these reasons we decided to suggest a reference model of a computer-supported collaborative learning environment which specifies the most important functionalities needed to overcome separation in time and space and the mechanisms by means of which those functionalities can be implemented. Besides that some additional tools can be integrated that can facilitate human thought through appropriate processing and presentation of information in such a form that is easier to understand.

Harasim [Hara91], [Hara92] identified eleven functions of computer-supported collaborative learning environment that can efficiently support education in general. Rekkdal and Paulsen [Rekk89] prepared a similar list of functions with slightly different emphasis.

After careful examination of both lists we selected a subset of functions that are most significant for specific requirements of problem based learning environments for distributed working groups. According to classification, introduced by McGrath and Hollingshead [McGr94], the functions of computer supported environment for collaboration can be divided into four groups where components in particular group are used to support functions concerning:

• access to external knowledge sources,
• external communication,
• communication in a group, and
• structuring group task performance.

The first group of mechanisms consists of tools that are used to access different external information resources that are needed by students in the process of problem solving. Some of these resources can be collected and structured in virtual textbooks, which represent a collection of specific learning materials, prepared for particular subject of study or particular course [Ruge97]. Nowadays widely available technologies support multimedia representation of information and we can talk about multimedia virtual textbooks. They can be implemented in different ways. Very often they are stored on CDs, but they can also be stored on private servers, accessible via local network, or on public servers anywhere in the cyberspace. In this form they represent a substitute for traditional library.

As problem based learning is interdisciplinary, students can not find all information they need in a single textbook or in textbooks covering only specific subject . They need more freedom in information inquiry process. It is clear that the Internet with all its services for information retrieval can meet most needs. World Wide Web with all corresponding multimedia tools represents a synonym for a tool for access to external knowledge sources.

On the other hand, too much freedom and abundance of information can provoke confusion and feeling experienced by the students that they are lost in the cyberspace. At this point interventions from advisors or sometimes consultations in the group are needed. Skilful handling with the tools (e.g. searching machines) and consistent requirement formulation are very important for effective work.

Whilst in the previous section we considered access to different information systems and databases, in this section we are concerned with communication with people, who do not belong to a group of students and is not formally engaged in group activities as a tutor.

The most common communication pattern for external communication is one-to-one; i.e. a single member of a group communicates with an individual outside the group on behalf of the group or on his behalf. In this respect, external communication is very similar to the concepts for an access to the (external) information sources.

In problem based learning environments this approach is mainly used to get some specific information from individual experts. Email is the most popular and the most convenient tool for this type of interaction.

This group of functions is certainly most significant for the implementation of computer-supported collaborative learning environment. While the first two groups of functionalities are not very specific in comparison with individual work, i.e. we can use practically the same tools and mechanisms as for traditional individual learning and working, group activities ask for specific support. Characteristic communication patterns for collaboration in a group are one-to-many and many-to-many. It is well known that these patterns are not well supported as one-to-one communication pattern is prevailing in traditional environments.

Most important activities that need special support are:

• small group discussion and debating teams,
• learning partnership and dyads,
• peer counseling,
• team presentations (moderated by students),
• shared document repository,
• group authoring tools, and
• informal socializing.

We consider the cases where members of a group for different reasons can not meet face-to-face and most of work is carried out by means of the computer supported collaborative environment.

The first three activities in the list above (i.e. small group discussion and debating teams, learning partnership and dyads and peer counseling) can be successfully implemented in computer conferencing systems, which represent widely available collaboration tool for one-to-many and many-to-many communication pattern. In the cases where only a two students are involved or when the discussion in not interesting for other members of a group, email can be used. If the students want to accelerate their work and they can participate in "a virtual group meeting", some synchronous tools for collaboration can be used. Internet Relay Chat (IRC) and similar tools (e.g. MUD) can be used for interaction. The problem is relatively low information throughput of these tools. Desktop multimedia conferencing tools, including video and audio, that allow much higher throughput, are getting more and more popular and accessible for mass use.

Communication throughput requirements depend on information richness required by particular activities and play an important role in the design of collaborative learning environment. In principle, communication channels represent a bottleneck for information exchange in any distributed system. Even the best tools for communication support can hardly deal with the amount of information that is adequate to performances of human sense organs. It is evident that the characteristics of communication channels between members of a group have a strong impact on the quality of collaborative work. It is not difficult to measure the throughput of a particular communications medium technically (e.g. in bits/sec), but there is no simple relation between the measured throughput and the efficiency of group work. Particular activities differ substantially as regards information richness. The richer is particular task, the higher throughput of communication channels is required and the more efficiency degradation results from the throughput limitations.

Activities requiring groups to generate ideas is on the low richness end. They only require transmission of specific ideas; emotional and evaluative connotations about message and source are not required and are even considered to be a hindrance. Intellective problems (i.e. problems "to choose") consider situations where a single correct answer or preferred solution exists. Situation is uncertain or ambiguous when a given group or its members have limited information available about the situation at a given time, but that missing information could be obtained. Activities requiring groups to solve intellective problems lie in between two extremes, on the low richness end. Tasks of the type "to judge" are characteristic for situations that are equivocal, e.g. they can be viewed from more than one perspective and can be taken to have more than one meaning. It is obvious that these activities lie on the high richness end. Negotiations and conflicts resolving activities require transmission of maximally rich information, including not only facts, but also values, attitudes, affective messages, expectations, and commitments.

Team presentations in most cases require synchronous approach to be effective. Shared whiteboard application, as a part of multimedia desktop conferencing systems, integrated into collaborative environment, is certainly the best solution. It allows controlled and synchronized presentation of text and different type of images. Together with audio and video channels it represents an environment which is really very close to traditional face-to-face meetings. An alternative is coordinated or guided presentation of WWW documents [Alto96].

Shared document repositories and group authoring tools can be implemented in many different ways. Recently, many advanced, generally applicable WWW based systems to support cooperation of distributed groups have been developed. The BSCW shared workspace [Appe96], as the most popular representative of these systems, is a document storage and retrieval system extended with features to support collaborative information sharing. A shared workspace can contain different kinds of information, such as documents, pictures, URL links, and threaded discussions. BSCW server is an extension of a WWW server and the last version of the system is completely implemented by means of CGI scripts. This means that in principle any WWW server can be extended to a BSCW server. Consequently, common WWW browsers can be used as BSCW clients. More details about the integration of WWW based systems for distributed group support into our learning environment can be found in [Ruge97a].

Since social communication is an essential component of education activity, online educational environments should provide opportunities for informal discourse. An online cafe as a metaphor for informal socializing can contribute to a sense of community among the users, forging a social bond that may offer motivational and cognitive benefits. There are many telematics services that can be used to implement "cyber cafe" (e.g. IRC, MUD, desktop conferencing).

The activities from this group are generally intended to improve both speed and quality of group productivity. There are many functionalities needed in newly developed distributed environments, supported by different technologies, for which no adequate tool has been developed and implemented. This is an area in which lack of interest in theoretical considerations has limited systematic development [McGr94].

For this reason computer supported collaborative environments still rely heavily on traditional mechanisms for coordination and management that are used in face-to-face collaboration settings.

An increasing number of educators and technologists believe that computer and communication technologies can provide a vehicle to help facilitate the evolution of a more appropriate, responsive, and effective educational system. The penetration of technology into learning process can have profound consequences for how learning takes place socially

Computer supported collaborative learning environment allows for much more diversified and socially rich learning context by means of email, computer and desktop multimedia conferencing as well as other innovative teleinformatics services in computer networks. The role of the teacher can be radically changed within a technology-rich learning process, with less time pressure to teach specific topics, more variated interactions with students, diversification of competences, and with interactions with a number of new professional figures that may enter the learning process.