Interactive Refinement Of Hierarchical Object Graphs

Developers need to understand the runtime structure of object-oriented code, and abstract object graphs can help. To extract abstract object graphs that convey design intent in the form of object hierarchy, additional information is needed to express this hierarchy in the code using ownership types, but adding ownership type qualifiers after the fact involves manual overhead, and requires developers to switch between adding qualifiers in the code and looking at abstract object graphs to understand the object structures that the qualifiers describe. We describe an approach where developers express their design intent by refining an object graph directly, while an inference analysis infers valid qualifiers in the code. A separate extraction analysis then uses these qualifiers and extracts an updated object graph. We implement and test the approach on several small test cases and confirm its feasibility

A VISUAL DESIGN METHOD AND ITS APPLICATION TO HIGH RELIABILITY HYPERMEDIA SYSTEMS

This work addresses the problem of the production of hypermedia documentation for applications that require high reliability, particularly technical documentation in safety critical industries. One requirement of this application area is for the availability of a task-based organisation, which can guide and monitor such activities as maintenance and repair. In safety critical applications there must be some guarantee that such sequences are correctly presented. Conventional structuring and design methods for hypermedia systems do not allow such guarantees to be made. A formal design method that is based on a process algebra is proposed as a solution to this problem. Design methods of this kind need to be accessible to information designers. This is achieved by use of a technique already familiar to them: the storyboard. By development of a storyboard notation that is syntactically equivalent to a process algebra a bridge is made between information design and computer science, allowing formal analysis and refinement of the specification drafted by information designers. Process algebras produce imperative structures that do not map easily into the declarative formats used for some hypermedia systems, but can be translated into concurrent programs. This translation process, into a language developed by the author, called ClassiC, is illustrated and the properties that make ClassiC a suitable implementation target discussed. Other possible implementation targets are evaluated, and a comparative illustration given of translation into another likely target, Java

Distributed software design for collaborative learning system over the Internet

Thesis (S.B. and M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1998.Includes bibliographical references (leaves 166-168).by Christine Hui Su.S.B.and M.Eng

Overcoming difficulties in learning calculus concepts : the case of Grade 12 students

Research has indicated the importance of calculus knowledge for undergraduate programs in science and technology fields. Unfortunately, one of the main challenges faced by students who join science and technology fields is their knowledge of calculus concepts. The main purpose of the study is to overcome students‟ difficulties in learning calculus concepts by developing a literature informed intervention model. A design-based research approach of three phases was conducted. Grade 12 natural science stream students in one administrative zone in Ethiopia were used as the study population. Triangulated themes of students‟ difficulties and common conceptual issues that are causes of these synthesized difficulties in calculus were used as a foundation to propose an intervention model. Based on the proposed model, an intervention was prepared and administered. A pre post-test aimed to asses students‟ conceptual knowledge in calculus was used to examine the effect of the model. Quantitative analysis of the test revealed that the intervention has a positive effect. The experimental group score is better than the controlled group score with independent t-statistics, t = 4.195 with alpha =.05. In addition, qualitative analysis of the test revealed that students in the experimental group are able to overcome many of the difficulties. In particular, many students demonstrated process level conception, conceptual reasoning, qualitative justification, a consistency in reasoning, less algebraic error, and a proficiency in symbolic manipulation. The study concludes with Implications for practice that includes the use of students‟ errors and misconceptions as an opportunity for progression. Besides, students should be assisted to make sense of concepts through real-life problems, including training teachers in problem-solving approaches and mathematical thinking practice.Mathematics EducationD. Phil (Mathematics, Science and Technology Education in the subject Mathematics Education

The development of multiplicative thinking and proportional reasoning: Models of conceptual learning and transfer

This thesis considers the development of multiplicative thinking and proportional reasoning from two perspectives. Firstly, it examines the research literature on progressions in conceptual understanding to create a Hypothetical Learning Trajectory (HLT). Secondly, it surveys modern views of how transfer by learners occurs in and between situations, contrasting object views of abstraction with knowledge in pieces views. Case studies of six students aged 11-13 years illustrate conceptual changes that occur during the course of a school year. The students are involved in a design experiment in which I (the researcher) co-teach with the classroom teacher. The students represent a mix of gender, ethnicity and level of achievement. Comparison of the HLT with the actual learning trajectory for each student establishes its validity as a generic growth path. Examination of the data suggests that two models of learning and by inference, transfer, describe the conceptual development of the students. There is consideration of students’ use of anticipated actions on physical and imaged embodiments as objects of thought with a focus on the significance of object creation for conceptual growth, and the encapsulation, completeness and contextual detachment of objects. There is broad consistency in students’ progress through the phases of the HTL within each sub-construct though the developmental patterns of individual are variable and temporal alignment across the sub-constructs does not uniformly hold. Some consistency of order effect in concept development is noted. Discussion on the limitations of the HTL includes the difference between knowledge types from a pedagogical perspective, absence of significant model-representation-situation transfer, and order relations in conceptual development. Considerable situational variation occurs as students solve problems that involve applications of the same concepts. Partial construction of concepts is common. This was true of all learners, irrespective of level of achievement. High-achieving students more readily anticipate actions and trust these anticipations as objects of thought than middle and low achievers. The data supports knowledge in pieces views of conceptual development. Complexity for learners in observing affordances in situations, and in co-ordinating the fine-grained knowledge required, explains the difficulty of transfer. While supporting the anticipation of action as significant from a learning perspective the research suggests that expertise in applying concepts involves a process of noticing similarity across contextually bound situations and cueing appropriate knowledge resources

Development of the Curriculum for the Introduction to Computer Science Course

This project proposes to reformat the curriculum for an Introduction to Computer Science course for high school students, currently taught as a one semester course. Several issues with the current course are addressed with recommendations for changes intended for the benefit of students at their school. In the past five years, enrollment in the school\u27s Advanced Placement (AP) Computer Science course has decreased from 50 students to 25 students despite no significant change in overall enrollment or student demographics. For the portion of those students enrolled in the course who have taken the Advanced Placement exam during the past four years, the passing rate was 50% to 100%. When students were encouraged to take the AP Computer Science A exam, a less rigorous exam, the passing rate increased. The school has been known to develop a curriculum that best meets the needs of its students. The current Introduction to Computer Science course is not meeting their needs. This project addresses several key aspects of the course that could be changed to better prepare the students for the Advanced Placement (AP) Computer Science course and increase enrollment in both the introductory and advanced courses, particularly (this would be an added bonus) with respect to female students. The key aspects with the Introduction to Computer Science course that this paper will address are as follows: 1. The effectiveness of the curriculum as an introduction to the Advanced Placement (AP) Computer Science, following the curriculum as outlined by the College Board. 2. The course objectives such as the educational philosophy of the course, how the students will be introduced to object-oriented programming using java, the programming language used in the AP Computer Science course, and choosing the software, textbook and supplemental materials that would best meet the needs of the students and support the course objectives. 3. The classroom teaching methodology. This would include, but not be limited to, the expectations of the students both in the classroom and as it relates to homework beyond class times, the nature of homework assignments, when and how much would be assigned on a daily basis, the types of assessments that would determine the students grades, and how these assessment would be graded. 4. Building student interest in the computer science field and demonstrating that every student is capable of basic programming skills

The OPEN software engineering process architecture: from activities to techniques

The 1997 OPEN process metamodel was the first fully documented software engineering process architecture for object-oriented projects, predating the Catalysis method, Select Perspective and the still emerging Rational Unified Process by a number of years. The OPEN process metamodel is based on a three-tier architecture, in which process Activities are broken down into a number of distinct Tasks; and each Task may be achieved through the application of a number of approved Techniques. This paper describes the relationships between the three layers of the OPEN process metamodel and shows how OPEN's Techniques contribute to a particular tailored process. As an exemplar, we describe Techniques relevant to late design and coding