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Case study

21 一月, 2016 - 14:46

The described service oriented ITS architecture has been tested during the implementation of the ITS for the graduate course “Artificial Intelligence” taught at Riga Technical University (Bicans et al, 2011). The course covers general artificial intelligence topics, like agents, planning, ontologies and reasoning. It has video and text learning materials with different levels of granularity. The video LOs are filmed lectures of the course. Materials cover theory, examples and tasks about the topics of the course. The aim of the ITS is to provide out of classroom tutoring, that takes into consideration learning styles of students by presenting a single or a combination of appropriate materials in each topic. The ITS stores and identifies all kinds of LOs describing them with standardized metadata. Links between topics and corresponding learning materials are not stored in the repositories. They are created dynamically. A keyword based algorithm is used to find the materials that can be used at the current topic and select the most suitable materials for the learner’s preferences. LOs and topics are described with keywords and if the intersection between the sets of LO’s topic’s keywords is possible, the LO is considered as linked to the topic. Then only those LOs that match the preferences stored in the student model are selected from the results’ set of the first step (Bicans, et al, 2011). Such an approach provides ITS with option to use more LOs from different repositories without manually linking LOs and topics. The curriculum of the course is encoded by a topic map that is a graphical knowledge representation form using topics and associations among them. In the developed ITS a topic map is used to show the hierarchy of the topics, because it visually shows the place of each topic in the course.

The general service oriented ITS architecture is customized during the development of the system to meet its specific needs. The main focus of the developed ITS prototype is on the adaptive LO presentation to learners. Therefore, only corresponding services dealing with LO selection, student model development, tutor’s functionality are implemented in the current version of the system. The actual architecture of the ITS is shown in Figure 12.7. The communication module contains the main interface service and two more higher level services – the topic map viewer service (visualizes curriculum) and the main material visualisation service, which also has two lower level services that visualize both types of

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Figure 12.7 The actual architecture of the implemented ITS prototype 

LOs used in the system – text and video LOs. The student module just has to maintain static student’s profiles. Thus it contains just one service named student modelling service. The tutoring module is implemented using two higher level services, named topic map creation service (curriculum generation service) and LO loading service used to retrieve LOs. It has two lower level services corresponding to both types of LOs. The teacher’s module besides the main interface service has services for editing topic maps, as well as for LO metadata editing and LO storing. Finally, the system has one additional module – system evaluation module, whose main task is to collect evaluations of the system provided by the learners.

The user interface of the system is given in Figure 12.8. The given screenshot is shown to the student when he/she chooses the topic to watch the video about. The menu is in the top left corner of the window (not included in the figure). The centre of the screen is occupied with the video player. One of the main parts of the system is shown in the bottom part of the figure. During the video session the system displays topics that are covered within lecture and related content that corresponds to the selected topic. Also, related topics, lectures and LOs are shown, allowing the learner to navigate to any related topic or material.

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Figure 12.8 The user interface of the developed ITS prototype 

The group of 19 students have approbated the developed ITS. They watched videos, red theoretical materials of lectures and explored examples. The feedback showed that granularity of LOs should vary, because some students like LOs with low granularity, while others prefer LOs with high granularity. The videos were used frequently and on average each student viewed 90% of available videos at least once. Another encouraging result is that 90% of students pointed out topic maps as appropriate tool to visualize the curriculum.