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Task model

21 January, 2016 - 14:46

A task model is a key model when a software product is developed. Using a model-driven technique for development, it is possible to provide important elements of our software product from a task model. Meaningful examples of it can be shown in (Limbourg,Vanderdonckt, Michotte, Bouillon, & López Jaquero, 2005; UsiXML).

In an e-Learning system the task model does not lose magnitude and, as for any other highly interactive systems, the task model is very important. With it we can specify the different tasks associated with teaching and learning process, highlighting those operations that teachers and students make.

Complexity of task model specification is even more intense when a collaborative system is specified and developed. This fact becomes more evident if we consider the new teaching and learning techniques CATs (Johnson, Johnson, & Smith, 1991; Heller, Keith, & Anderson, 1992; Aronson, Blaney, Stephan, Sikes, & Snapp, 1978).

To carry out our contribution first we review the available task analysis and modelling notations. In this sense, the best positioned notation is the ConcurTaskTrees (Mori, Paternò, & Santoro, 2002), we found that this notation is one of the most promising notations, even though, from our point of view it presents some limitation to model collaborative tasks, and in the other side it does not present any limitation for modelling cooperative tasks. In addition, this notation is widespread in the interaction field and has a well-established track record. The problem that we identified is that the temporal operators are not always sufficient to specify when a task starts or finishes.

We will return to this point in a later section to describe this limitation with more detail. In addition, traditional task model notations are not completely intuitive (see Figure 15.3) for a novice people in general, for non-familiarities with it. And others problems can be mentioned too, for instant scalability or collaborative facilities are weak points.

Based on this context, we finished identifying and introducing a new notation. That notation was a Gantt chart-based notation (Maylor H., 2001; Wilson J. M., 2003). This notation is identified like suitable for task model specification because it is intuitive, easy of understand, easy of learn, scalable, flexible, and it is possible to specify collaborative and cooperative tasks.

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Figure 15.3 A task model sample with Concur Task Tree notation 

In our eLearniXML notation (see Figure 15.4) we can represent, as in a CTT specification,concurrent and sequential tasks and there is also an immediate feedback according to their development, from the start till the end of the tasks. This aspect is mainly interesting to us for the development and specification of software products of e-Learning systems, where without becoming interactive systems with critical characteristics when considering the time, this element is essential.

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Figure 15.4 Sample of eLearniXML Task-Oriented notation 

With this task model, eLearniXML is an effective notation for planning and scheduling operations involving a minimum of dependencies and interrelationships among the activities. The technique is best applied to activities for which time durations is necessary to estimate, since there is no provision for treatment of uncertainty. On the other hand, eLearniXML tasks are easy to construct and understand, even though they may contain a great amount of information. In general, the tasks are easily maintained provided the taskrequirements are somewhat static.

So, the advantages of using our task model for e-Learning systems versus other task notation, such as CTT or CUA: Collaboration Usability Analysis (Pinelle, Gutwin, & Greenberg, 2004) notations are gathered as follows:

  • Clarity, easy to understand: one of the biggest benefits of the eLearniXML task is the notation ability to boil down multiple tasks and timelines into a single document. Stakeholders throughout an organization can easily understand where teams are in a process while grasping the ways in which independent elements come together toward lesson and activities completion.
  • Learn-ability: self-understanding of the use of the notation. ELearniXML has the capability of to enable end users (Teachers and Students) to learn how to use it. This advantage is considered as an aspect of usability, and is of major concern in the design of complex applications.
  • Communication: teachers by using eLearniXML notation replace meetings and enhance other status updates. Simply clarifying task positions offers an easy, visual method to help teachers understand activities progress.
  • Motivation: teachers become more effective when faced with a form of external motivation. ELearniXML notation offer teachers the ability to focus work at the front of a task/activity timeline, or at the tail end of a task segment. Both types of team members can find eLearniXML notations meaningful as they plug their own workhabits into the overall e-Lesson schedule.
  • Coordination: the benefits of the eLearniXML notation include the ability to sequence activities for the management of e-Lessons and its resources by teachers. Teachers can even use combinations of tasks to break down e-Lessons into more manageable sets of activities.
  • Creativity: sometimes, a lack of time or resources forces teachers to find creative solutions. Seeing how individual activities intertwine on eLearniXML notation often encourages new partnerships and collaborations that might not have evolved under traditional activities.
  • Time Management: teachers regard scheduling as one of the major benefits of eLearniXML notation in a creative environment over the other notations. Helping teachers to understand the overall impact of the lessons delays can foster stronger collaboration while encouraging better activities organization.
  • Flexibility: the facility to issue new tasks notation, with eLearniXML, as the teacher’s e-Lesson evolves lets him react to unexpected changes in the e-Lessons scope or timeline. While revising his e-Lesson schedule offering him a realistic view of an e-Lesson can help teachers recover from setbacks or adjust to other changes.
  • Manageability: the benefits of eLearniXML notation include externalizing assignments.By visualizing all of the tasks of an activity and all the activities of an e-Lesson, so teachers can make more focused, effective decisions about the used resources and timetables.
  • Efficiency: another one of the benefits of eLearniXML notation is the ability for teachers to leverage each other’s deadlines for maximum efficiency. For instance, while one teacher waits on the outcome of three other tasks before starting a crucial piece of the activity, he or she can perform other e-Lesson tasks. Visualizing resource usage during e-Lessons allows teachers to make better use of students, teaching, and teaching techniques.

After showing the benefits of using eLearniXML notation, the way in which it represents its tasks process, we shall start to present the task model description.