Roger G. Stone

On the choice of grammar and parser for the compact analytical encoding of programs

Le codage analytique englobe le codage par derivation et le codage par analyse syntaxique et a pour but de representer le programme

An improved representation for evolving programs

A representation has been developed that addresses some of the issues with other Genetic Program representations while maintaining their advantages. This combines the easy reproduction of the linear representation with the inheritable characteristics of the tree representation by using fixed-length blocks of genes representing single program statements. This means that each block of genes will always map to the same statement in the parent and child unless it is mutated, irrespective of changes to the surrounding blocks. This method is compared to the variable length gene blocks used by other representations with a clear improvement in the similarity between parent and child. In addition, a set of list evaluation and manipulation functions was evolved as an application of the new Genetic Program components. These functions have the common feature that they all need to be 100% correct to be useful. Traditional Genetic Programming problems have mainly been optimization or approximation problems. The list results are good but do highlight the problem of scalability in that more complex functions lead to a dramatic increase in the required evolution time.

Selection of touch gestures for children’s applications: repeated experiment to increase reliability

The touch-screen revolution is not restricted to adults only. Parents find games and educational applications running on touch-screen devices and purchase them for their children. Therefore, very young children are playing with and exploring these touch-screen devices. For any one device there can be hundreds of applications for the parents to choose from, so it is likely that the selection of applications is based on advertisements and recommendations. There is a large range of gestures available on multi-touch devices and there is very little known about the relationship between the age of a child and the gestures that they can master. This research focuses on the iPad device and children aged between 2 to 4 years old and investigate which gestures the children in that age group can manage. The results of the research, therefore, could be used to form guidelines for the design of gesture-based software for very young children.

Integrating Accessibility and Functional Requirements

Initial research on Web accessibility was focused on testing completed Web pages. More recently, the focus is moving to integrating accessibility features into coding tools such as Dreamweaver 8 and plugins notably LIFT. Thus accessibility is being considered slightly earlier in the development process. However, the state of Web accessibility is still disappointing even on websites that have followed the guidelines and or used evaluation and coding tools. We are proposing an approach to start considering accessibility much earlier. Our purpose is to address accessibility in the context of what is to be done and who will be participating. In this paper, we present views of Web developers about this approach. We then show (using a case study) how Web developers can elicit accessibility requirements alongside functional requirements and integrate the two to obtain conceptual models with explicit traces of accessibility requirements integrated with functional requirements. Finally we discuss lessons learnt from the case study and common benefits of the approach for Web accessibility and Web projects.

Proving the validity and accessibility of dynamic web-pages

If a static web-page is checked for accessibility and passes then all is well. However checking the accessibility of the output from a dynamic (scripted) web-page is like testing a program to find errors. However many times a test succeeds it is always possible that the program will produce bad output next time. What is needed is something closer to a proof of correctness. This paper describes a first attempt to provide a proof of validity for dynamic web-pages which can be extended to a proof of accessibility.

A framework for filtering web accessibility guidelines

This paper first presents a framework for filtering the Web Accessibility Guidelines according to contexts of use. It then presents a prototype that implements the framework and explains an evaluation of the prototype.

Reasoning Consistently about Inconsistency

Patching et al. and Hinde et al. in their work on truth-space mass assignments, presented a semantic unification function and a semantic separation function for mass assignment logic that dealt with inconsistency. This paper takes these two functions and while preserving the outside inconsistencies shows how inconsistency can be reasoned about in a consistent manner. This means that inconsistency that arises outside the system need not enter the system, but needs to be represented within the system, and can therefore be extracted appropriately as output from the system to emerge as inconsistency on the outside. The internal reasoning system need therefore only concern itself with belief in truth, falsity and uncertainty.

Profile-based web document delivery

This work originated by considering the needs of visually impaired users but may have wider application. A profile captures some key descriptors or preferences of a user and their browsing device. Individual users may maintain any number of profiles which they can edit for use in different situations, for different tasks or with different devices. A profile is described in terms of essentiality and proficiency. Essentiality is used to control the quantity of information that is transmitted and proficiency is used to control the format. Various levels of essentiality are introduced into a document by the technique known as microformatting. Proficiency (for the visually impaired) includes a description of minimum acceptable font size, preferred font face and preferred text and background colours. A key feature of the proficiency profile is the accessibility component which captures the users tolerance of accessibility issues in a document, for example the presence of images or the markup of tables. The document delivery tool works as a kind of filter to reduce the content to the level of essentiality requested, to make the various presentation changes and to warn of accessibility issues as specified in the users profile. Encouraging preliminary results have been obtained from testing the prototype with subjects from the local RNIB college.

Personalised feedback with semi-automated assessment tool for conceptual database model

Abstract The increased presence of diagram-type student work in higher education has recently attracted researchers to look into the automation of diagram marking. This paper intro duces web-based diagram drawing and marking tools for a new (semi-automatic) assessment approach. The approach reduces the number of diagram components marked by the human marker and provides individualised and detailed feedback to students. The tools have been used in tutorials of a first year database module in the Computer Science department at Loughborough University are described together with findings from the usage of the tools.

Yet another storage technique for LR parsing tables

A submatrix storage scheme for sparse matrices is presented which has been found useful for storing LR parsing tables. It is not the most compact representation but it is easy to use and of order (1) in speed of access. The method is compared with the two most popular methods of storing LR parsing tables which use ‘linear lists’ and ‘row displacement’. Results of using the submatrix method to store the parsing tables for the Pascal language are included.