Improving Novice Analyst Performance in Modeling the Sequence Diagram in Systems Analysis: A Cognitive Complexity Approach

The Unified Modeling Language (UML) has quickly become the industry standard for object-oriented software development. It is being widely used in organizations and institutions around the world. However, UML is often found to be too complex for novice systems analysts. Although prior research has identified difficulties novice analysts encounter in learning UML, no viable solution has been proposed to address these difficulties. Sequence-diagram modeling, in particular, has largely been overlooked. The sequence diagram models the behavioral aspects of an object-oriented software system in terms of interactions among its building blocks, i.e. objects and classes. It is one of the most commonly-used UML diagrams in practice. However, there has been little research on sequence-diagram modeling. The current literature scarcely provides effective guidelines for developing a sequence diagram. Such guidelines will be greatly beneficial to novice analysts who, unlike experienced systems analysts, do not possess relevant prior experience to easily learn how to develop a sequence diagram. There is the need for an effective sequence-diagram modeling technique for novices. This dissertation reports a research study that identified novice difficulties in modeling a sequence diagram and proposed a technique called CHOP (CHunking, Ordering, Patterning), which was designed to reduce the cognitive load by addressing the cognitive complexity of sequence-diagram modeling. The CHOP technique was evaluated in a controlled experiment against a technique recommended in a well-known textbook, which was found to be representative of approaches provided in many textbooks as well as practitioner literatures. The results indicated that novice analysts were able to perform better using the CHOP technique. This outcome seems have been enabled by pattern-based heuristics provided by the technique. Meanwhile, novice analysts rated the CHOP technique more useful although not significantly easier to use than the control technique. The study established that the CHOP technique is an effective sequence-diagram modeling technique for novice analysts.

Integration and querying of heterogeneous, autonomous, distributed database systems

Today, databases have become an integral part of information systems. In the past two decades, we have seen different database systems being developed independently and used in different applications domains. Today's interconnected networks and advanced applications, such as data warehousing, data mining & knowledge discovery and intelligent data access to information on the Web, have created a need for integrated access to such heterogeneous, autonomous, distributed database systems. Heterogeneous/multidatabase research has focused on this issue resulting in many different approaches. However, a single, generally accepted methodology in academia or industry has not emerged providing ubiquitous intelligent data access from heterogeneous, autonomous, distributed information sources. This thesis describes a heterogeneous database system being developed at Highperformance Database Research Center (HPDRC). A major impediment to ubiquitous deployment of multidatabase technology is the difficulty in resolving semantic heterogeneity. That is, identifying related information sources for integration and querying purposes. Our approach considers the semantics of the meta-data constructs in resolving this issue. The major contributions of the thesis work include: (i.) providing a scalable, easy-to-implement architecture for developing a heterogeneous multidatabase system, utilizing Semantic Binary Object-oriented Data Model (Sem-ODM) and Semantic SQL query language to capture the semantics of the data sources being integrated and to provide an easy-to-use query facility; (ii.) a methodology for semantic heterogeneity resolution by investigating into the extents of the meta-data constructs of component schemas. This methodology is shown to be correct, complete and unambiguous; (iii.) a semi-automated technique for identifying semantic relations, which is the basis of semantic knowledge for integration and querying, using shared ontologies for context-mediation; (iv.) resolutions for schematic conflicts and a language for defining global views from a set of component Sem-ODM schemas; (v.) design of a knowledge base for storing and manipulating meta-data and knowledge acquired during the integration process. This knowledge base acts as the interface between integration and query processing modules; (vi.) techniques for Semantic SQL query processing and optimization based on semantic knowledge in a heterogeneous database environment; and (vii.) a framework for intelligent computing and communication on the Internet applying the concepts of our work.

From phenomenography study to planning teaching

A phenomenographic study uncovers variations in the way that the subjects are aware of a phenomenon. In the categories of description that represent the variations in awareness there are features that, through their variation, define the characteristics of the categories. Teaching seeks to foster a change in the way that the learner is aware of a phenomenon through opening up a space of learning. This paper outlines the way that the outcome spaces from a phenomenographic study can be used to plan a teaching programme that utilises variations in the features. It discusses a strategy for teaching programming based on a phenomenographic study of practitioner conceptions of an object-oriented program. The strategy covers features related to the nature of an object-oriented program. Copyright 2010 ACM.

The user's view level of the GOQL graphical query language

The paper addresses issues related to the design of a graphical query mechanism that can act as an interface to any object-oriented database system (OODBS), in general, and the object model of ODMG 2.0, in particular. In the paper a brief literature survey of related work is given, and an analysis methodology that allows the evaluation of such languages is proposed. Moreover, the user's view level of a new graphical query language, namely GOQL (Graphical Object Query Language), for ODMG 2.0 is presented. The user's view level provides a graphical schema that does not contain any of the perplexing details of an object-oriented database schema, and it also provides a foundation for a graphical interface that can support ad-hoc queries for object-oriented database applications. We illustrate, using an example, the user's view level of GOQL

UNDERSTANDING ESSAY RATING AS A SOCIALLY MEDIATED ACTIVITY: THE CASE OF A HIGH-STAKES ENGLISH TEST IN CHINA

Most essay rating research in language assessment has examined human raters’ essay rating as a cognitive process, thus overlooking or oversimplifying the interaction between raters and sociocultural contexts. Given that raters are social beings, their practices have social meanings and consequences. Hence it is important to situate essay rating within its sociocultural context for a more meaningful understanding. Drawing on Engeström’s (1987, 2001) cultural-historical activity theory (CHAT) framework with a sociocultural perspective, this study reconceptualized essay rating as a socially mediated activity with both cognitive (individual raters’ goal-directed decision-making actions) and social layers (raters’ collective object-oriented essay rating activity at related settings). In particular, this study explored raters’ essay rating at one provincial rating centre in China within the context of a high-stakes university entrance examination, the National Matriculation English Test (NMET). This study adopted a multiple-method multiple-perspective qualitative case study design. Think-aloud protocols, stimulated recalls, interviews, and documents served as the data sources. This investigation involved 25 participants at two settings (rating centre and high schools), including rating centre directors, team leaders, NMET essay raters who were high school teachers, and school principals and teaching colleagues of these essay raters. Data were analyzed using Strauss and Corbin’s (1990) open and axial coding techniques, and CHAT for data integration. The findings revealed the interaction between raters and the NMET sociocultural context. Such interaction can be understood through a surface structure (cognitive layer) and a deep structure (social layer) concerning how raters assessed NMET essays, where the surface structure reflected the “what” and the deep structure explained the “how” and “why” in raters’ decision-making. This study highlighted the roles of goals and rules in rater decision-making, rating tensions and raters’ solutions, and the relationship between essay rating and teaching. This study highlights the value of a sociocultural view to essay rating research, demonstrates CHAT as a sociocultural approach to investigate essay rating, and proposes a direction for future washback research on the effect of essay rating. This study also provides support for NMET rating practices that can potentially bring positive washback to English teaching in Chinese high schools.

IMPROVING THE PERFORMANCE OF DATABASE-CENTRIC APPLICATIONS THROUGH PROGRAM ANALYSIS

Modern software applications are becoming more dependent on database management systems (DBMSs). DBMSs are usually used as black boxes by software developers. For example, Object-Relational Mapping (ORM) is one of the most popular database abstraction approaches that developers use nowadays. Using ORM, objects in Object-Oriented languages are mapped to records in the database, and object manipulations are automatically translated to SQL queries. As a result of such conceptual abstraction, developers do not need deep knowledge of databases; however, all too often this abstraction leads to inefficient and incorrect database access code. Thus, this thesis proposes a series of approaches to improve the performance of database-centric software applications that are implemented using ORM. Our approaches focus on troubleshooting and detecting inefficient (i.e., performance problems) database accesses in the source code, and we rank the detected problems based on their severity. We first conduct an empirical study on the maintenance of ORM code in both open source and industrial applications. We find that ORM performance-related configurations are rarely tuned in practice, and there is a need for tools that can help improve/tune the performance of ORM-based applications. Thus, we propose approaches along two dimensions to help developers improve the performance of ORM-based applications: 1) helping developers write more performant ORM code; and 2) helping developers configure ORM configurations. To provide tooling support to developers, we first propose static analysis approaches to detect performance anti-patterns in the source code. We automatically rank the detected anti-pattern instances according to their performance impacts. Our study finds that by resolving the detected anti-patterns, the application performance can be improved by 34% on average. We then discuss our experience and lessons learned when integrating our anti-pattern detection tool into industrial practice. We hope our experience can help improve the industrial adoption of future research tools. However, as static analysis approaches are prone to false positives and lack runtime information, we also propose dynamic analysis approaches to further help developers improve the performance of their database access code. We propose automated approaches to detect redundant data access anti-patterns in the database access code, and our study finds that resolving such redundant data access anti-patterns can improve application performance by an average of 17%. Finally, we propose an automated approach to tune performance-related ORM configurations using both static and dynamic analysis. Our study shows that our approach can help improve application throughput by 27--138%. Through our case studies on real-world applications, we show that all of our proposed approaches can provide valuable support to developers and help improve application performance significantly.

Jigsaw Java: Intelligent, Automated Marking

The popularity of Computing degrees in the UK has been increasing significantly over the past number of years. In Northern Ireland, from 2007 to 2015, there has been a 40% increase in acceptances to Computer Science degrees with England seeing a 60% increase over the same period (UCAS, 2016). However, this is tainted as Computer Science degrees also continue to maintain the highest dropout rates.
In Queen’s University Belfast we currently have a Level 1 intake of over 400 students across a number of computing pathways. Our drive as staff is to empower and motivate the students to fully engage with the course content. All students take a Java programming module the aim of which is to provide an understanding of the basic principles of object-oriented design. In order to assess these skills, we have developed Jigsaw Java as an innovative assessment tool offering intelligent, semi-supervised automated marking of code.
Jigsaw Java allows students to answer programming questions using a drag-and-drop interface to place code fragments into position. Their answer is compared to the sample solution and if it matches, marks are allocated accordingly. However, if a match is not found then the corresponding code is executed using sample data to determine if its logic is acceptable. If it is, the solution is flagged to be checked by staff and if satisfactory is saved as an alternative solution. This means that appropriate marks can be allocated and should another student have submitted the same placement of code fragments this does not need to be executed or checked again. Rather the system now knows how to assess it.
Jigsaw Java is also able to consider partial marks dependent on code placement and will “learn” over time. Given the number of students, Jigsaw Java will improve the consistency and timeliness of marking.

O impacto da utilização de design patterns nas métricas e estimativas de projetos de software: a utilização de padrões tem alguma influência nas estimativas?

VALENTIM, R. A. M. ; SOUZA NETO, Plácido Antônio de. O impacto da utilização de design patterns nas métricas e estimativas de projetos de software: a utilização de padrões tem alguma influência nas estimativas?. Revista da FARN, Natal, v. 4, p. 63-74, 2006

From Kandinsky to Java (The Use of 20th Century Abstract Art in Learning Programming)

At the University of Worcester we are continually striving to find new approaches to the learning and teaching of programming, to improve the quality of learning and the student experience. Over the past three years we have used the contexts of robotics, computer games, and most recently a study of Abstract Art to this end. This paper discusses our motivation for using Abstract Art as a context, details our principles and methodology, and reports on an evaluation of the student experience. Our basic tenet is that one can view the works of artists such as Kandinsky, Klee and Malevich as Object-Oriented (OO) constructions. Discussion of these works can therefore be used to introduce OO principles, to explore the meaning of classes, methods and attributes and finally to synthesize new works of art through Java code. This research has been conducted during delivery of an “Advanced OOP (Java)” programming module at final-year Undergraduate level, and during a Masters’ OO-Programming (Java) module. This allows a comparative evaluation of novice and experienced programmers’ learning. In this paper, we identify several instructional factors which emerge from our approach, and reflect upon the associated pedagogy. A Catalogue of ArtApplets is provided at the associated web-site.

Database evolution on an orthogonal persistent programming system: A semi-transparent approach

In this paper the problem of the evolution of an object-oriented database in the context of orthogonal persistent programming systems is addressed. We have observed two characteristics in that type of systems that offer particular conditions to implement the evolution in a semi-transparent fashion. That transparency can further be enhanced with the obliviousness provided by the Aspect-Oriented Programming techniques. Was conceived a meta-model and developed a prototype to test the feasibility of our approach. The system allows programs, written to a schema, access semi-transparently to data in other versions of the schema.

Classification multi-échelle d'images à très haute résolution spatiale basée sur une nouvelle approche texturale

Résumé : Face à l’accroissement de la résolution spatiale des capteurs optiques satellitaires, de nouvelles stratégies doivent être développées pour classifier les images de télédétection. En effet, l’abondance de détails dans ces images diminue fortement l’efficacité des classifications spectrales; de nombreuses méthodes de classification texturale, notamment les approches statistiques, ne sont plus adaptées. À l’inverse, les approches structurelles offrent une ouverture intéressante : ces approches orientées objet consistent à étudier la structure de l’image pour en interpréter le sens. Un algorithme de ce type est proposé dans la première partie de cette thèse. Reposant sur la détection et l’analyse de points-clés (KPC : KeyPoint-based Classification), il offre une solution efficace au problème de la classification d’images à très haute résolution spatiale. Les classifications effectuées sur les données montrent en particulier sa capacité à différencier des textures visuellement similaires. Par ailleurs, il a été montré dans la littérature que la fusion évidentielle, reposant sur la théorie de Dempster-Shafer, est tout à fait adaptée aux images de télédétection en raison de son aptitude à intégrer des concepts tels que l’ambiguïté et l’incertitude. Peu d’études ont en revanche été menées sur l’application de cette théorie à des données texturales complexes telles que celles issues de classifications structurelles. La seconde partie de cette thèse vise à combler ce manque, en s’intéressant à la fusion de classifications KPC multi-échelle par la théorie de Dempster-Shafer. Les tests menés montrent que cette approche multi-échelle permet d’améliorer la classification finale dans le cas où l’image initiale est de faible qualité. De plus, l’étude effectuée met en évidence le potentiel d’amélioration apporté par l’estimation de la fiabilité des classifications intermédiaires, et fournit des pistes pour mener ces estimations.

Orientation de l’effort des tests unitaires dans les systèmes orientés objet : une approche basée sur les métriques logicielles

Les logiciels actuels sont de grandes tailles, complexes et critiques. Le besoin de qualité exige beaucoup de tests, ce qui consomme de grandes quantités de ressources durant le développement et la maintenance de ces systèmes. Différentes techniques permettent de réduire les coûts liés aux activités de test. Notre travail s’inscrit dans ce cadre, est a pour objectif d’orienter l’effort de test vers les composants logiciels les plus à risque à l’aide de certains attributs du code source. À travers plusieurs démarches empiriques menées sur de grands logiciels open source, développés avec la technologie orientée objet, nous avons identifié et étudié les métriques qui caractérisent l’effort de test unitaire sous certains angles. Nous avons aussi étudié les liens entre cet effort de test et les métriques des classes logicielles en incluant les indicateurs de qualité. Les indicateurs de qualité sont une métrique synthétique, que nous avons introduite dans nos travaux antérieurs, qui capture le flux de contrôle ainsi que différentes caractéristiques du logiciel. Nous avons exploré plusieurs techniques permettant d’orienter l’effort de test vers des composants à risque à partir de ces attributs de code source, en utilisant des algorithmes d’apprentissage automatique. En regroupant les métriques logicielles en familles, nous avons proposé une approche basée sur l’analyse du risque des classes logicielles. Les résultats que nous avons obtenus montrent les liens entre l’effort de test unitaire et les attributs de code source incluant les indicateurs de qualité, et suggèrent la possibilité d’orienter l’effort de test à l’aide des métriques.

O impacto da utilização de design patterns nas métricas e estimativas de projetos de software: a utilização de padrões tem alguma influência nas estimativas?

VALENTIM, R. A. M. ; SOUZA NETO, Plácido Antônio de. O impacto da utilização de design patterns nas métricas e estimativas de projetos de software: a utilização de padrões tem alguma influência nas estimativas?. Revista da FARN, Natal, v. 4, p. 63-74, 2006

Diseño de una herramienta modular que facilite la implementación del Banco de Proyectos de la Fundación Red de Apoyo Social de Antioquia – RASA, ubicado en la ciudad de Medellín, entre el periodo 2014-2 y 2015-1

Los usuarios reales y potenciales del sistemas de salud en Colombia, encuentran en el camino de acceso a los servicios múltiples barreras, debido a las diferentes carencias que éste sistema presenta. Para apoyar las necesidades del usuario en éste tema de acceso, se constituyó en el año 2006 la Fundación RASA, quien ofrece de manera gratuita, a la comunidad en general, mecanismos de exigibilidad, acceso y protección de sus derechos en temas de salud. Este trabajo de grado, pretende dar un valor agregado diseñando una herramienta modular que facilite la implementación del banco de proyectos, con el fin de mejorar sus procesos y sea referencia para otras entidades dedicadas a velar por el bienestar de los individuos, en virtud de su objeto social orientado a la protección de derechos en temas de salud, además se realiza con el fin de Optar por el Título de Especialista en Alta Gerencia de la Universidad de Medellín. Con el fin de entender las necesidades de La Fundación RASA, será primordial conocer y tener un manejo adecuado de la teoría de la organización; teniendo clara su vertiente descriptiva que sugiere lo que se debe hacer para mejorar varios aspectos de la empresa, en éste caso la necesidad de diseñar un Banco de Proyectos. El trabajo se ha estructurado de la siguiente manera: Referente Teórico, Contextualización De La Fundación Rasa, Diseño De Una Herramienta Modular (Introducción, Objetivos, Recursos, Metodología y procedimientos, Evaluación y Monitoreo, Responsable de proceso, Presupuesto Estructural), Conclusiones y Recomendaciones.

Sharing the vision: representing the matters of concern for design-led fledgling companies in Scotland

Design is being performed on an ever-increasing spectrum of complex practices arising in response to emerging markets and technologies, co-design, digital interaction, service design and cultures of innovation. This emerging notion of design has led to an expansive array of collaborative and facilitation skills to demonstrate and share how such methods can shape innovation. The meaning of these design things in practice can't be taken for granted as matters of fact, which raises a key challenge for design to represent its role through the contradictory nature of matters of concern. This paper explores an innovative, object-oriented approach within the field of design research, visually combining an actor-network theory framework with situational analysis, to report on the role of design for fledgling companies in Scotland, established and funded through the knowledge exchange hub Design in Action (DiA). Key findings and visual maps are presented from reflective discussions with actors from a selection of the businesses within DiA's portfolio. The suggestion is that any notions of strategic value, of engendering meaningful change, of sharing the vision of design, through design things, should be grounded in the reflexive interpretations of matters of concern that emerge.