Designing a programming-based approach for modelling scientific phenomena

We describe an iteratively designed sequence of activities involving the modelling of 1- dimensional collisions between moving objects based on programming in ToonTalk. Students aged 13-14 in two settings (London and Cyprus) investigated a number of collision situations, classified into six classes based on the relative velocities and masses of the colliding objects. We describe iterations of the system in which students engaged in a repeating cycle of activity for each collision class: prediction of object behaviour from given collision conditions, observation of a relevant video clip, building a model to represent the phenomena, testing, validating and refining their model, and publishing it – together with comments – on our web-based collaboration system, WebReports. Students were encouraged to consider the limitations of their current model, with the aim that they would eventually appreciate the benefit of constructing a general model that would work for all collision classes, rather than a different model for each class. We describe how our intention to engage students with the underlying concepts of conservation, closed systems and system states was instantiated in the activity design, and how the modelling activities afforded an alternative representational framework to traditional algebraic description

Identification of Design Principles

This report identifies those design principles for a (possibly new) query and transformation language for the Web supporting inference that are considered essential. Based upon these design principles an initial strawman is selected. Scenarios for querying the Semantic Web illustrate the design principles and their reflection in the initial strawman, i.e., a first draft of the query language to be designed and implemented by the REWERSE working group I4

Pervasive Parallel And Distributed Computing In A Liberal Arts College Curriculum

We present a model for incorporating parallel and distributed computing (PDC) throughout an undergraduate CS curriculum. Our curriculum is designed to introduce students early to parallel and distributed computing topics and to expose students to these topics repeatedly in the context of a wide variety of CS courses. The key to our approach is the development of a required intermediate-level course that serves as a introduction to computer systems and parallel computing. It serves as a requirement for every CS major and minor and is a prerequisite to upper-level courses that expand on parallel and distributed computing topics in different contexts. With the addition of this new course, we are able to easily make room in upper-level courses to add and expand parallel and distributed computing topics. The goal of our curricular design is to ensure that every graduating CS major has exposure to parallel and distributed computing, with both a breadth and depth of coverage. Our curriculum is particularly designed for the constraints of a small liberal arts college, however, much of its ideas and its design are applicable to any undergraduate CS curriculum

CS Circles: An In-Browser Python Course for Beginners

Computer Science Circles is a free programming website for beginners that is designed to be fun, easy to use, and accessible to the broadest possible audience. We teach Python since it is simple yet powerful, and the course content is well-structured but written in plain language. The website has over one hundred exercises in thirty lesson pages, plus special features to help teachers support their students. It is available in both English and French. We discuss the philosophy behind the course and its design, we describe how it was implemented, and we give statistics on its use.Comment: To appear in SIGCSE 201

Using SVG and XSLT for graphic representation

Using SVG and XSLT for graphic representation In this paper we will present an XML based framework that can be used to produce graphical visualisation of scientific data. The approach rather than producing ordinary histogram and function diagaram graphs, tries to represent the information in a more graphical appealing and easy to understand way. For examples the approach will give the ability to represent the temperature as the level of coulored fluid in a thermometer. The proposed framework is able to maintain the value of the datas strictly separated from the visual form of its representation (positions of element, colours, visual representation etc.). By defining appropriate data structures and expressing them using XML, the framework gives the user the ability to create graphic representations using standard SVG and XSLT. Since XML can be used for describing complex data information, we represent every level of the graphic representation with an XML structure. To describe our architecture we defined the following XML dialects, each one with different markup tags, reflecting the semantical values of the elements. Data definition level. Used to define the value of the datas that can be used in the graphic representation Data representation level. Used to define the graphic representation, it defines how the values expressed by the data definition level are represented. Both data representation and data definition files are based on a DTD to impose the constraints. Data representation level is the core of the system, and defines a powerful language for representation. Source primitives. Used to define for the source of the graphic elements, for example static file or SVG code. Modification primitives. Used to define the modifications that can affect a graphic element, for example rotation, scaling or repetition. Disposition primitives. Used to define the possible dispositions along x, y and z axes, for example to impose a order in the representation of elements. Action primitives. Used to define the possible actions that canbe activated by graphic elements for different user behaviours. For example a mouse action can activate a link to a different resource, or can change the value of any of the other primitives of the data structure, as image source or disposition, or can show a tooltip . XSLT is used to output a SVG file derived from the two files describing the graphic representation. Our aim is to provide an abstract language to be used to represent in different ways the same concept. In fact, we can link a data definition file with different data representation levels, providing different kinds and levels of complexity for the same concept. An example use could be the representation of the temperature described before, where the temperature itself could be represented either as the level of mercury in the termomether, or as the rotation of an arrow in a gauge. The transformation process is made from an XML source tree into an XML result tree, using XPath to define patterns. XSLT transformation process is based on templates, that define some actions (like adding or removing elements, or sorting them) to be performed when a part of the document matches a template. To implement some of the complex graphics operations we are using XSLT extensions that allow to perform mathematical operations. These XSLT extensions are not yet standard and require specific compliant parser, as Apache Xalan, that allows the developer to interface with Java classes in order to increase XSLT areas of application, from simple node transformations to quite complex operations

Translation into any natural language of the error messages generated by any computer program

Since the introduction of the Fortran programming language some 60 years ago, there has been little progress in making error messages more user-friendly. A first step in this direction is to translate them into the natural language of the students. In this paper we propose a simple script for Linux systems which gives word by word translations of error messages. It works for most programming languages and for all natural languages. Understanding the error messages generated by compilers is a major hurdle for students who are learning programming, particularly for non-native English speakers. Not only may they never become "fluent" in programming but many give up programming altogether. Whereas programming is a tool which can be useful in many human activities, e.g. history, genealogy, astronomy, entomology, in many countries the skill of programming remains confined to a narrow fringe of professional programmers. In all societies, besides professional violinists there are also amateurs. It should be the same for programming. It is our hope that once translated and explained the error messages will be seen by the students as an aid rather than as an obstacle and that in this way more students will enjoy learning and practising programming. They should see it as a funny game.Comment: 14 pages, 1 figur