Ray Welland

Comprehension of diagram syntax: an empirical study of entity relationship notations

Well-defined symbolic notations are essential for communication between teams of people working on any application. For large software implementations, UML is commonly used, for databases, entity relationship (ER) diagrams are useful. However, the form of notation used in texts, papers, and documentation and learning materials is often different, and tends to reflect the personal preference of the author or publisher. The choice between semantically equivalent notations does not appear to be based on any consideration of the ease with which human readers could understand the notation. This paper addresses this notation comprehension issue by proposing an experimental methodology for determining which of two complete notations is easier to comprehend. The methodology also allows individual notational variants to be targeted. This methodology has been applied to two types of ER notations: our experiment required subjects to indicate whether a supplied textual specification of objects and relationships matched each of a set of Chen (Chen, ACM Trans. Database Systems 1 (1976) 9) and SSADM (Weaver, Practical SSADM Version 4-A Complete Tutorial Guide, Pitman, London, 1993) ER diagrams. The results reveal both better performance and higher preference for the more concise overall notation, with partial results with respect to individual variants within the notations.

Collecting Feedback during Software Engineering Experiments

Objective: To improve the qualitative data obtained from software engineering experiments by gathering feedback during experiments. Rationale: Existing techniques for collecting quantitative and qualitative data from software engineering experiments do not provide sufficient information to validate or explain all our results. Therefore, we would like a cost-effective and unobtrusive method of collecting feedback from subjects during an experiment to augment other sources of data. Design of study: We formulated a set of qualitative questions that might be answered by collecting feedback during software engineering experiments. We then developed a tool to collect such feedback from experimental subjects. This feedback-collection tool was used in four different experiments and we evaluated the usefulness of the feedback obtained in the context of each experiment. The feedback data was triangulated with other sources of quantitative and qualitative data collected for the experiments. Results: We have demonstrated that the collection of feedback during experiments provides useful additional data to: validate the data obtained from other sources about solution times and quality of solutions; check process conformance; understand problem solving processes; identify problems with experiments; and understand subjects’ perception of experiments. Conclusions: Feedback collection has proved useful in four experiments and we intend to use the feedback-collection tool in a range of other experiments to further explore the cost-effectiveness and limitations of this technique. It is also necessary to carry out a systematic study to more fully understand the impact of the feedback-collecting tool on subjects’ performance in experiments.

Web development evolution: the assimilation of Web engineering security

In todays e-commerce environment, information is an incredibly valuable asset. Surveys indicate that companies are suffering staggering financial losses due to Web security issues. Analyzing the underlying causes of these security breaches shows that a significant proportion of them are caused by straightforward design errors in systems and not by failures in security mechanisms. There is significant research into security mechanisms but there is little research into the integration of these into software design processes, even those processes specifically designed for Web Engineering. Security should be designed into the application development process upfront through an independent flexible methodology that contains customizable components.

Fully Integrated Data Environments

This text provides an introduction to Tycoon l , an open persistent polymorphic programming environment. The Tycoon language TL is based on expressive and orthogonal naming, typing and binding concepts as they are required, for example, in advanced dataintensive applications. The characteristic language mechanisms of TL are first -class functions and modules, parametric and sUbtype polymorphism extended to a fully higher-order type system. Tycoon programs are statically typed but may include explicit dynamic type variables which can be inspected at run-time.

Agile web engineering (AWE) process: multidisciplinary stakeholders and team communication

The Agile Web Engineering (AWE) Process is an agile or light-weight process that has been created to tackle the challenges that have been identified in Web engineering: short development life-cycle times; multidisciplinary development teams; delivery of bespoke solutions comprising software and data. AWE helps teams identify and manage the interactions between the business, domain, software and creative design strands in Web engineering projects. This paper gives an overview of the wide diversity of stakeholder roles reflected within AWE and how AWE tries to ensure communication between multidisciplinary sub-teams on large Web engineering projects.

Web engineering security: a practitioner's perspective

There are a number of critical factors driving security in Web Engineering. These include: economic issues, people issues, and legislative issues. This paper presents the argument that a Security Improvement Approach (SIA), which can be applied to different Web engineering development processes, is essential to successfully addressing Web application security. In this paper, the criteria that any SIA will have to address, for a Web engineering process, are presented. The criteria are derived with supporting empirical evidence based on an in-depth security survey conducted within a Fortune 500 financial service sector organization and supporting literature. The contribution of this paper is two fold. The criteria presented in this paper can be used to assess the security of an existing Web engineering process and also to guide Security Improvement Initiatives in Web Engineering.

Analysing Persistent Language Applications

Most research into persistent programming has been directed towards the design and implementation of languages and object stores. There are few reports on the characteristics of systems exploiting such technology. This paper reports on a study of the source code of 20 applications consisting of more than 108,000 lines of persistent language code. The authors of the applications range from students to experienced programmers. The programs have been categorised and examined with respect to a persistent application model and the extent of inconsistencies relative to this model is presented. The results confirm the need for and give input to the design of programming methodologies and tools for persistent software engineering. Measurements also include the use of names, types, (polymorphic) procedures and persistent bindings. It is hoped that analysis of the measurements will be used as input to the next generation of languages and programming environments. As part of this new generation, a measurements system is outlined operating entirely within the persistent environment, thus simplifying access to and measurement of both static and dynamic information.

The ECLIPSE user interface

This paper describes the user interface facilities of the ECLIPSE integrated project support environment. This interface is based on a consistent metaphor called the ‘control panel’ metaphor and includes standard help and message‐handling systems. The paper describes these as well as some of the interface standards which have been developed. The interface has been implemented on top of the ‘applications interface’, which provides a portable, hardware‐independent interface for software tools.

Evaluation of Commercial Web Engineering Processes

Over the past five years a small number of specific commercial processes and evolutions to traditional software engineering processes for Web Engineering have been proposed. The existing Web engineering literature focuses mainly on techniques and tools that underpin the process of building Web applications, with little or no focus on the commercial suitability of the Web Engineering processes themselves. Based on our experience and surveys of Web engineering in practice, we have defined a set of essential criteria to be addressed by a commercial Web engineering process. In this paper we present a systematic evaluation of a sample of commercial Web engineering processes against these criteria. None of the commercial Web engineering processes evaluated addresses all the identified criteria. Ultimately to address the criteria for a Web engineering process there is a need for a different type of process.

Method rule checking in a generic design editing system

This paper describes a means of incorporating method rule checking in a design editing system intended to support the production of designs expressed in method-specific diagrammatic notations. The novel characteristic of this editing system is the fact that it may be tailored to any notation using a method description language and a graphical tool to define the vocabulary of the notation. Syntactic and semantic rules are expressed in the method description language and are checked, interactively, during an editing session.