Policy-based planning for student mobility support in e-Learning systems
Student mobility in the area of Higher Education (HE) is gaining more attention nowadays. It is one of the cornerstones of the Bologna Process being promoted at both national and international levels. However, currently there is no technical system that would support student mobility processes and assist users in authoring educational curricula involving student mobility. In this study, the problem of student mobility programmes generation based on existing modules and programmes is considered. A similar problem is being solved in an Intelligent Tutoring Systems field using Curriculum generation techniques, but the student mobility area has a set of characteristics limiting their application to the considered problem. One of main limiting factors is that mobility programmes should be developed in an environment with heterogeneous regulations. In this environment, various established routines and regulations are used to control different aspects of the educational process. These regulations can be different in different domains and are supported by different authors independently. In this thesis, a novel framework was developed for generation of student mobility programmes in an environment with heterogeneous regulations. Two core technologies that were coherently combined in the framework are hierarchical planning and policy-based management. The policy-based planner was designed as a central engine for the framework. It extends the functionality of existing planning technologies and provides the means to carry out planning in environments with heterogeneous regulations, specified as policies. The policy-based planner enforces the policies during the planning and guarantees that the resultant plan is conformant with all policies applicable to it. The policies can be supported by different authors independently. Using them, policy authors can specify additional constraints on the execution of planning actions and extend the pre-specified task networks. Policies are enforced during the planning in a coordinated manner: situations when a policy can be enforced are defined by its scope, and the outcomes of policy evaluation are processed according to the specially defined procedures. For solving the problem of student mobility programme generation using the policy-based planner, the planning environment describing the student mobility problem area was designed and this problem was formalised as a planning task. Educational processes valid throughout the HE environment were formalised using Hierarchical Task Network planning constructs. Different mobility schemas were encoded as decomposition methods that can be combined to construct complex mobility scenarios satisfying the user requirements. New mobility programmes are developed as detailed educational processes carried out when students study according to these programmes. This provides the means to model their execution in the planning environment and guarantee that all relevant requirements are checked. The postponed policy enforcement mechanism was developed as an extension of the policy-based planner in order to improve the planning performance. In this mechanism, future dead-ends can be detected earlier during the planning using partial policy requests. The partial policy requests and an algorithm for their evaluation were introduced to examine policies for planning actions that should be executed in the future course of planning. The postponed policy enforcement mechanism was applied to the mobility programme generation problem within the descending policy evaluation technique. This technique was designed to optimise the process of programme components selection. Using it, policies for different domains can be evaluated independently in a descending order, gradually limiting the scope for the required component selection. The prototype of student mobility programme generation solution was developed. Two case studies were used to examine the process of student mobility programmes development and to analyse the role of policies in this process. Additionally, four series of experiments were carried out to analyse performance gains of the descending policy evaluation technique in planning environments with different characteristics.
- PhD