Publications

 Deadlocks are a common error in programs with lock-based concurrency and are hard to avoid or even to detect. One way for deadlock prevention is to statically analyze the program code to spot sources of potential deadlocks. Often static approaches try to confirm that the lock-taking adheres to a given order, or, better, to infer that such an order exists. Such an order precludes situations of cyclic waiting for each other’s resources, which constitute a deadlock.

In contrast, we do not enforce or infer an explicit order on locks. Instead we use a behavioral type and effect system that, in a first stage, checks the behavior of each thread or process against the declared behavior, which captures potential interaction of the thread with the locks. In a second step on a global level, the state space of the behavior is explored to detect potential deadlocks. We define a notion of deadlock-sensitive simulation to prove the soundness of the abstraction inherent in the behavioral description. Soundness of the effect system is proven by subject reduction, formulated such that it captures deadlock-sensitive simulation.

 A complete first order logic called Neighbourhood Logic to model hybrid systems is first proposed by Zhou and Hansen. Two neighbourhood modalities are introduced and it is shown that the logic is complete, adequate and suitable for modelling hybrid-systems. In AI literature, reasoning and representing indefinite temporal information of qualitative nature have been elaborately studied and this study originates from Allen's proposal of Interval Algebra. Since the satisfiability problem for Interval Algebra is established to be NP-complete, the main research has been to determine maximal tractable sub-algebras of Allen' algebra. It is observed that the Neighbourhood Logic provides an elegant interpretation of the results related to the tractability of Interval Algebra and the algorithmic study of the Interval Algebra provides some foundational insight to decidability class of Neighbourhood Logic. The present study is concerned with these two aspects of the Neighbourhood Logic formalism for Interval Algebra.

Computer aided hardware/software partitioning is one of the key challenges in hardware/software co-design. This paper describes a new approach to hardware/software partitioning for synchronous communication model. We transform the partitioning into a reachability problem in timed automata. By means of an optimal reachability algorithm, an optimal result can be obtained in terms of limited resources in hardware. To increase the opportunity of partitioning optimization, two algorithms are designed to explore the dependency relation among processes in the initial specification. Moreover, we propose a scheduling algorithm to improve the synchronous communication efficiency further after partitioning stage. Some experiments are conducted with model checker UPPAAL to show our approach is both effective and efficient.

 This report presents the basic foundations for the verification by means of model checking techniques of formal specifications expressed in RAISE. During this work, third party model checkers are briefly discussed and analysed for suitability under two main criteria: (a) syntactic/semantic restrictions imposed by the model checker's language and (b) the applied representation technique for the system (i.e. symbolic or explicit). Then, the selection of Symbolic Analysis Laboratory (SAL) as the model checking tool is justified and all RAISE syntactic constructions are analysed for transformation into SAL. Foundations for the semantic preservation during the translation are provided in the cases where the justification is not a trivial one. Finally, the design of extensions to RAISE to define transition systems and to support temporal logic formulas is described and the tool that implements the first version of the described translation procedure is also reported

This study presents how the degree of script coercion can affect the learning outcome in a setting for computer-supported collaborative learning. In the study, 42 junior students majoring in Informatics were randomly assigned into two study conditions: High Coercion (n=22), and Low Coercion (n=20). Initially, students worked individually, studying material and answering ill-structured problems on the Software Project Management domain in a technology-enhanced learning environment. Next, students worked in pairs reviewing each other’s answers, following a review microscript. Eventually, the students had to collaborate and agree on a final common answer. Post-test result analysis showed that students obligated to submit their review comments as deliverables back into the learning environment (High Coercion) far surpassed those for whom review submission as deliverables was optional. This outcome is in line with studies emphasizing that learning is improved when technology tools require that learners make their thinking explicit.

This work explores the role of students’ motivation and metacognitive skills as moderating factors that influence the impact of an instructional method in the ill-structured domain of Software Project Management (SPM). In order to teach aspects of the SPM domain, we developed a web environment for case-based learning and implemented additionally a questioning strategy to help students focus on important parts of the case material. The paper presents the results from three studies revealing how students’ motivation and metacognitive awareness influenced their engagement in the cognitively challenging situations induced by the method. The implication for instructors and designers is that implementing a promising method to help students efficiently process the complex material in an ill-structured domain might not always lead to the desired learning outcomes. Students’ motivation and metacognitive skills should also be addressed in order to maximize the potential benefits of instruction.

This study investigates the effectiveness of two variants of a prompting strategy that guides students to focus on important issues when learning in an ill-structured
domain. Students in three groups studied individually Software Project Management (SPM) cases for a week, using a web-based learning environment designed especially for
this purpose. The first group (control) studied the cases without any prompting. The second group (‘‘writing mode’’) studied the same cases, while prompted to provide written
answers to a set of knowledge integration prompts meant to engage students in deeper processing of the material. The third group (‘‘thinking mode’’) studied the cases, while
prompted only to think of possible answers to the same question prompts. Results indicated that students in the writing condition group outperformed the others in both domain knowledge acquisition and knowledge transfer post-test items. Several students in the thinking condition group skipped the question prompts, while those that reported having reflected on the material were unable to achieve high performance comparable to the writing condition group. Overall, the study provides evidence that the implementation of prompting techniques in technology-enhanced learning environments may lead to improved outcomes, when combined with the requirement that students provide their answers in writing.

Software project management (SPM) is an ill-structured domain, where past experiences of project management can become valuable learning resources for novices. To support instruction in the domain, we have developed the eCASE-SPM Web environment, for engaging students in case-based instruction and help them develop SPM related problem solving skills. This work presents major design issues of the environment and initial research results regarding (a) a student-based evaluation, connecting also students’ attitudes to their learning styles, and (b) the learning effectiveness of the environment, investigating the use of embedded question prompts as students’ cognitive scaffolds. Results so far reveal interesting interactions between students’ learning styles and their attitudes towards learning in the eCASE-SPM environment. Furthermore, there is strong indication that using question prompts may have beneficial effect on students’ learning and problem solving abilities, although fading out of the scaffolding should be implemented to moderate students’ workload. 

This paper presents design guidelines for implementing a free-selection peer review protocol. “Free-selection” (FS) refers to the ability of students freely access all available peer work and choose which of them to read and review. A series of two studies on the free-selection protocol has provided evidence on the efficiency of the method. In the First study, the FS protocol was compared against the widely used assigned-pair one, where students work in instructor-defined dyads. In the Second study, further issues of the FS approach were evaluated, with our attention focused on students who, due to the freedom element of the protocol, do not receive reviews. Both studies paint a very promising picture of free-selection. However, several issues were also raised on how to effectively apply such a protocol. As the use of technology is necessary in the FS approach, we provide in this paper the design implications derived from the two studies regarding, (a) peer work availability, (b) non-reviewed works, (c) student population, (d) peer work visual representation, (e) peer work length, (f) presentation order, (g) double-blinded approach, (h) peer reviews availability, and (i) students’ approaches in selecting peer work for reading and reviewing.

Across the Arab world, Classical Arabic, and its derived form, Modern Standard Arabic (MSA), are perceived as the “high” form of language, whereas the local “dialects” are usually perceived negatively. In Qatar, this discrepancy between the two forms of Arabic is further reinforced by the fact that MSA is taught in schools as the official language and used in official documents, as well as in news channels (e.g., Al Jazeera), whereas the dialect is used in all aspects of everyday life including the verbal communication between teachers and students. This diaglossic problem presents itself from the early grades of elementary school, but it is not being dealt with until students move to secondary school. By then, MSA and dialect are treated as two different languages, as it is difficult for the student to identify the connections between them. In most cases, the outdated teaching material adds to the problem, although one of our co-authors has proposed a new curriculum in Qatar aimed at enhancing MSA learning in elementary students.

Parallel to curricular reform, a three-year project is currently underway to utilize the affordances of technology-enhanced learning tools, in order to reform Arabic instruction in young students. This presentation will report on the first pilot study from this project.

More specifically, we are designing modules based on the story of Aladdin, a famous and loved story among young Arabic children. The learning environment will combine adapted short episodes of the story and intervening learning activities. The use of appealing images, themed music, and capturing voices will get students’ attention. The educational games will be age-appropriate so that the students will feel confident they are able to complete them and advance to the next episode. User satisfaction from the continuation of the story and the game rewards could increase engagement. Understanding the relevance between the activities and the learning goals is the most difficult issue to tackle, as the students have to possess the metacognitive skill to understand how this kind of activity can fulfill their goals (i.e., learning MSA, a goal that is not always shared among the students!). The teacher and a list of learning goals could help in this direction.

Going deeper into the activities, we feel that it is important to teach the children from a very young age that they are members of a bigger community, which is why we focus our attention on collaboration games. However, extra attention is needed in designing the educational game, as we do not want to have students with strong personality or higher level of knowledge to overshadow others during the game. Following Dillenbourg’s SWISH model (acronym of “Split When Interaction Should Happen”), no student will be able to complete an activity on their own. Hence, students will have to decide their next action and actually perform it in collaboration (e.g., moving two identical objects at the same time to different hot spots). Another characteristic that we are planning to implement in the games is competition between student groups. In this way we can increase engagement, although the level of competition should not act against the learning objectives. Even the losing teams will go forward to the next episode, while the winners will get an extra reward that will not interfere with the learning objectives of the next phase (e.g., change Aladdin’s skills or choose from alternative next episodes).

Finally, we had to decide on the technology that we would use. First of all, we needed a system that can support collaboration. This means many users, interacting at the same time. Second, the system had to be user-friendly, having in mind that our users are 7-year-olds with limited computer experience (use of mouse and keyboard). Third, it had to be ergonomic to support the formation of groups of students in the classroom. Based on the above, we decided to use surface computers, and more specifically SMART Tables, as they can fulfil our design needs.
 

Purpose – The purpose of this paper is to explore the impact of question prompts on student learning in relation to their learning styles. The context of the study is technology-enhanced learning in an ill-structured domain.
Design/methodology/approach – The study conditions were the same for all the students in the four learning style groups. Student learning style was the independent variable, while students’ attitudes and task performance were the dependent variables of the study. Pre-test treatment post-test method was used. Students studied in a web-based learning environment during treatment.
Findings – The integration of question prompts as student supporting tool in technology-enhanced learning environments might not improve learning for all students alike independent of their learning styles.
Research limitations/implications – Small uneven groups because the researcher has no control over the student distribution across the different learning style profiles.
Practical implications – The suggestion for designers is to consider combining prompting with other scaffolding methods, in order to effectively support all students independent of their learning styles.
Originality/value – The paper combines learning in ill-structured domains through cases and a scaffolding method based on question prompts focusing on contextual elements. The results of the study inform the designers of TELEs that although prompting can be generally helpful, parameters such as the students’ learning style are able to limit the cognitive benefit emerging from the prompting intervention.

This work focuses on the efficiency of question prompts for supporting students, when learning through cases in an ill-structured domain, such as Software Project Management. Three groups of students studied cases in a lab-session time period using a web-based environment, where question prompts directed students to think on important issues of the case material. The first group studied the cases without the question prompts, the second group studied, while prompted to provide written answers to questions embedded in the cases, and the third group studied and was asked only to think of possible answers for the question prompts. Post-tests did not reveal any significant differences between the three groups. This result is discussed in the light of a previous study, which showed that this kind of prompting may have beneficial impact on student learning in a prolonged study-time setting, where students are able to self-regulate their study activity.

This paper presents the results after three years of running of an instructional method that utilizes free/libre open source software (FLOSS) projects as tools for teaching software engineering in formal education. In the last three academic years, a total of 268 juniors majoring in Informatics (in a 4-year program) participated in study, assuming the roles of testers, developers, and requirements engineers. Students appreciated the benefits gained by the method and identified aspects that require further improvement. In the following, we present (a) the details of our method, (b) students’ opinions as recorded through a questionnaire including both closed and open ended questions, and (c) conclusions on how the use of FLOSS projects can be applied and proved beneficial for the students.

This study analyzes the benefits and limitations of a “free-selection” peer assignment protocol by comparing them to the widely implemented “assigned-pair” protocol. The primary motivation was to circumvent the issues that often appear to the instructors implementing peer review activities with pre-assigned groups, without posing additional workload to the instructor or diminishing the learning outcomes. In the study, 36 sophomore students in a Computer Networking course were randomly assigned into two conditions: 20 in Assigned-Pair, where the students worked in pre-defined dyad, and 17 in Free-Selection, where students were able to explore and select peer work for review. Result analysis showed a very strong tendency in favor of the Free-Selection students regarding both domain specific (conceptual) and domain-general (reviewing) knowledge.

This study was designed to investigate the impact of question prompts that guide students to focus on context-related issues when learning through cases in an illstructured
domain. Three groups of undergraduate students studied cases during a lab-session time period using a web-based environment. The first group studied without any
question prompts. The second group studied the same material while prompted to provide written answers to embedded questions in the cases. The third group studied while having only to think of possible answers for the question prompts. In this study, we explored how the questioning intervention affected students’ conceptual knowledge of the domain and their problem-solving ability. Post-tests did not reveal significant statistical differences in the groups’ performance, indicating that under specific study conditions the prompting impact is not traceable in the learning outcomes. This result, however, is discussed in the light of a previous study, which showed that this context-oriented prompting method had a beneficial effect on student learning in a prolonged study-time setting, where students were able to self-regulate their study activity.

This work analyzes a case of computer-supported scripted collaboration, focusing on how students’ self-organization affected the actual collaboration script during script run-time. Two groups of students studied learning material using a web environment designed for supporting case-based learning. The first group followed a non-scaffolded individual mode of study while students in the second group were guided by a collaboration script to work (in dyads) on the case material. Statistical analysis indicated no significant differences in the learning outcomes of the two groups. Qualitative analysis (based on students’ interviews and field observations) revealed that students’ self-organization resulted to a broad range of actual script implementation ranging from full conformance to partial violation of the script guidelines. The paper discusses the socio-cognitive role of students’ self-organization during scripted collaboration and presents suggestions for the teacher and CSCL designer in order to enhance the engagement of collaborating students to productive learning interactions.

This study provides field research evidence on the efficiency of a “free-selection” peer review assignment protocol as compared to the typically implemented “assigned-pair” protocol. The study employed 54 sophomore students who were randomly assigned into three groups: Assigned-Pair (AP) (the teacher assigns student works for review to student pairs), Free-Selection (FS) (students are allowed to freely explore and select peer work for review), and No Review (NR) (control group). AP and FS student groups studied and reviewed peer work in the domain of Computer Networking, supported by a web-based environment designed to facilitate the two peer review protocols. Our results indicate that students following the Free Selection protocol demonstrate (a) better domain learning outcomes, and (b) better reviewer skills, compared to the AP condition. Overall, the study analyzes the benefits and shortcomings of the FS vs AP review assignment protocol, providing evidence that the FS condition can be multiply beneficial to students who engage in peer review activities.

Case-based learning is expected to enhance students’ awareness of the various contextual factors, which affect problem solving in ill structured domains. An interesting question is always how to engage students in efficient processing of the case-based learning material. In this work, we present the design and preliminary evaluation results of the eCASE environment, a generic web-based environment for supporting case-based instruction. eCASE allows instructors to develop appropriate study paths for students to criss-cross the case-based information landscape. Furthermore, it supports students’ study by providing scripts, which scaffold them when processing the learning material. A script in eCASE models the cognitive processes related to context awareness and guides students to focus on important events, recall relative cases and reach useful conclusions. First evaluation results indicate that students acknowledge the learning efficiency of scripted material. However, design improvements are also necessary to make scripts more appealing and less monotonous for students.