Implementing technologies in developing communities often involves working with people that have a very different context from the researcher in terms of lower literacy and less experience with technology. Having worked with three rural communities in Uganda and introduced an Information and Communication Technology (ICT) intervention for water management, we use activity theory to analyse people's activities in relation to the use and uptake of the community-based ICT tool. To understand the contextual factors that influence the use of the tool, we proceed from our activity theory analysis and we unpack the perceptions and attitudes that rural technology users have towards technology. Our findings provide insights into what motivates and demotivates people in rural communities to use ICTs. We use our findings to substantiate the relevance of the intangible impacts of ICTs such as empowerment, social cohesion and improved self-worth for rural technology users. We recommend that technology designers be open to the unintended uses of the technologies they introduce in rural communities.

Most learners in resource-constrained environments own mobile phones that they could use to learn programming while outside the classroom. However, limitations of mobile phones, such as small screens and small keypads, impede their use as typical programming environments. This study proposed that programming environments on mobile phones could include scaffolding techniques specifically designed for mobile phones, and designed based on learners' needs. Scaffolding should be designed with some essential techniques that are mandatory for learners to use. Hence, one type of scaffolding technique that was designed to support programming on the mobile phone is static scaffolding that does not fade. Experiments were conducted with 64 learners of programming from three universities in Kenya and South Africa in order to investigate how they used the designed static scaffolding techniques to construct Java programs on a mobile phone. The results show that programming on mobile phones can be supported by providing scaffolding techniques that never fade, in order to address the limitations of mobile phones and to meet learners' needs.

Support for novice learners of computer programming can be provided by scaffolding the construction of programs. The ubiquity of mobile phones allows us to support learners whenever they wish to work on a program outside the classroom. This paper describes the development of an application that scaffolds the construction of programs on a mobile phone. The application was designed based on a five-level scaffolding framework and implemented on the Android platform.

In this study, we examine Information and Communication Technology for Development (ICT4D) technology interventions that have been developed over the last decade. The purpose is to provide a snapshot of the trends that have characterized ICT4D technology interventions from the period starting 1995 to 2010. This paper presents three general dimensions i.e. ICTs, development and research which are further broken down into seven variables used to categorize projects over this period. The seven variables include: telecommunication, terminal device, target group, domain area, region, research methods and discipline. Results suggest that applied research stood out as the methodology of choice; health and education as the most researched areas; hand-held interventions as the most popular choice of solutions; and Computer Science, Informatics and Information Systems as the disciplines that offer ICT4D technology interventions. Consequently, we argue that these trends will facilitate understanding the past performance of ICT4D, both as an academic field and as an area of development practice, and identify defining ideas on the potential directions for the future.

BACKGROUND: Centralised resources such as GenBank and UniProt are perfect examples of the major international efforts that have been made to integrate and share biological information. However, additional data that adds value to these resources needs a simple and rapid route to public access. The Distributed Annotation System (DAS) provides an adequate environment to integrate genomic and proteomic information from multiple sources, making this information accessible to the community. DAS offers a way to distribute and access information but it does not provide domain experts with the mechanisms to participate in the curation process of the available biological entities and their annotations. RESULTS: We designed and developed a Collaborative Annotation System for proteins called DAS Writeback. DAS writeback is a protocol extension of DAS to provide the functionalities of adding, editing and deleting annotations. We implemented this new specification as extensions of both a DAS server and a DAS client. The architecture was designed with the involvement of the DAS community and it was improved after performing usability experiments emulating a real annotation task. CONCLUSIONS: We demonstrate that DAS Writeback is effective, usable and will provide the appropriate environment for the creation and evolution of community protein annotation.

This paper describes a process for creating a design tool, which is based in constructivism. The process is described for the creation of a tool to help novices in designing virtual environment interactions, however it can be generalized to other design domains. The process consists of four steps: first constructivist values of atomic simplicity, multiplicity, exploration, control and reflection are distilled. Next, expert practices are researched and reframed in terms of the constructivist values. Thirdly, novice processes are examined and understood in constructivist terms. Lastly, prototypes are created and shown to target users. These steps are iterated until the designed tool is satisfactory.

User-centred design (UCD) is a well-accepted and useful design methodology for designing interactive systems. In recent years, developing world researchers have attempted to utilise UCD but with mixed results. The results from two developing world, UCD projects, MuTI Mobile and CyberTracker, have shown that the analysis tools and techniques provided by UCD are useful but difficulties arise when interpreting the analysis findings to produce a requirements specification. In particular, traditional UCD methodologies fail to consider the broader and complex effects of the user's physical and social environments. The field studies also highlighted the limitations of existing early-stage prototyping techniques, such as paper-prototyping. The authors address these issues by presenting several tools and techniques that they feel are more suited to the developing world and essential components of a candidate ‘UCD4Dev’ methodology. These tools and techniques include the use of ‘4Dev’ frameworks, such as the ‘Real Access/Real Impact’ criteria, to highlight pertinent developing world issues, the use of higher fidelity technology artefacts during early stage prototyping, the importance of developing a motivated user group and the need for a progressive participatory design approach.

We adapt the Flodar (Swing, 1998) metaphor to visualize dynamic networks and present experimental results on the effectiveness of this approach. Dynamic reconfiguration of networks enable rapid optimization of performance of a network, however, it poses several management difficulties when user intervention is required to resolve complex routing problems. Our metaphor scales well for networks of varying size, addresses the cluttering problem seen in past metaphors and maintains the overall network context while providing additional support for navigation and interaction. We apply the metaphor to three dynamic reconfiguration management tasks and show how these tasks are visually represented with our approach. We conducted an experiment with network administrators and researchers as subjects. A good understanding of network conditions portrayed in the metaphor was achieved within a short period.

Some multimedia archives contain data which have vague locations in time and space. By this we mean that, although there is some idea of when and where the entity is located, the precise information is unknown. In this paper, we present a novel approach to displaying and querying such uncertain data. We use the concepts of dynamic queries, add to this a 2D query tool for performing spatial queries and enable Boolean combinations of queries. We have implemented these ideas in a pilot system for querying African artwork. In this way, we show how it is possible for novice users to easily query large multimedia archives with complex uncertain attributes.

We present a new graphical representation of the level-of-detail state spaces generated by hierarchical geometric scene descriptions with multiple levels of detail. These level-of-detail graphs permit the analytical investigation of the hierarchical level-of-detail optimization problem that arises for such descriptions. As an example of their use, we prove the equivalence of two hierarchical level-of-detail algorithms.

We show that the hierarchical level of detail optimization problem is equivalent to a constrained version of the Multiple Choice Knapsack Problem, and present a new algorithm whose solution to it is at least half as good as the optimal one. The advantage of the hierarchical algorithm is that it allows the use of hierarchical level of detail descriptions in which shared representations may be provided for groups of objects. Rendering cost may then be saved to afford better renderings of more important objects, and the algorithm is capable of providing a complete representation of the visible scene even when the visible scene complexity is very high. Our algorithm has a worst case time complexity of O(nlogn), and is incremental so that it typically completes in only a few iterations. We introduce the use of perceptual evaluation to demonstrate the effectiveness of the use of representations for groups of objects that our algorithm allows.

Abstract We present a new algorithm here for efficient incremental rendering of volumetric datasets. The primary goal of this algorithm is to give average workstations the ability to efficiently render volume data received over relatively low bandwidth network links in such a way that rapid user feedback is maintained. Common limitations of workstation rendering of volume data include: large memory overheads, the requirement of expensive rendering hardware, and high speed processing ability. The rendering algorithm presented here overcomes these problems by making use of the efficient Shear‐Warp Factorisation method which does not require specialised graphics hardware. However the original Shear‐Warp algorithm suffers from a high memory overhead and does not provide for incremental rendering which is required should rapid user feedback be maintained. Our algorithm represents the volumetric data using a hierarchical data structure which provides for the incremental classification and rendering of volume data. This exploits the multiscale nature of the octree data structure. The algorithm reduces the memory footprint of the original Shear‐Warp Factorisation algorithm by a factor of more than two, while maintaining good rendering performance. These factors make our octree algorithm more suitable for implementation on average desktop workstations for the purposes of interactive exploration of volume models over a network. Results from tests using typical volume datasets will be presented which demonstrate the ability of the algorithm to achieve high rendering rates for both incremental rendering and standard rendering while reducing the runtime memory requirements.

A wavelet-based image-encoding is described which, when used in conjunction with the Difference Engine (a custom-designed VLSI display processor) allows us to reconstruct an image in real-time without the need to set each pixel explicitly. The image is compressed using a quadratic spline-wavelet transform; when reconstructing, an image-adaptive instruction generator attempts to produce the minimal instruction stream to give a good reproduction. The wavelet coefficients are used to decide which regions of the detail images should be retained in the multi-resolution analysis (MRA). A decision is made for each scan-line as to whether it is more economical, in terms of rendering time, to use the 'truncated MRA' or to set the pixels directly. The above approach provides a significant gain over standard image reconstruction/rendering schemes.>

Abstract A new algorithm, Mesh Propagation, is presented for the generation of isosurfaces from three‐dimensional discrete data sets. While producing the same surface mesh as that generated by a corrected Marching Cubes algorithm, its characteristic is that it constructs an isosurface using connected strips of dynamically triangulated polygons. This compact data structure speeds up surface construction and reduces surface storage requirements. The surface can also be displayed more quickly, particularly where there is hardware support for rendering triangle strips. With engineering as well as medical imaging applications in mind, the algorithm can be used with both irregular and rectilinear grids of data, the primitive volume elements need not be hexahedral only, and volumes of heterogeneous polyhedral elements are supported without traversal complications. The algorithm propagates through the cells in the grid and uses the same lookup table topologies as Marching Cubes to determine patches of surface‐element intersection; additional tables are used for non‐hexahedral elements. The surface patches are dynamically coded into triangle strips which are then concatenated and linked to construct the surface. The data structures used for propagating through the volume overcome the topological ambiguities associated with table‐based methods of surface construction and no holes are generated in the final mesh.

Abstract One of the most successful algorithms that brought realism to the world of 3D image generation is Phong shading. It is an algorithm for smooth shading meshes of planar polygons used to represent curved surfaces. The level of realism and depth perception that can be obtained by Phong shading is attractive for 3D CAD applications and related areas. However, per pixel computation costs which were too high and/or artifacts, introduced by some of the more efficient evaluation methods and apparent only when displaying moving objects, are major factors mat blocked the common usage of Phong shading in highly interactive applications. In this paper we present angular interpolation for Phong shading planar polygons. Angular interpolation was a method especially designed to meet requirements as imposed by special purpose hardware we developed1, but turned out to be generally applicable. The angular interpolation method appears to be very efficient and reduces artifacts when displaying moving objects. Ideally a shading algorithm imposes no need for subdivision of patches as presented by the solid modelling system. Shading calculation via angular interpolation yields such an ideal algorithm. We will describe two alternative evaluation methods that trade off evaluation cost against level of accuracy. They both can handle light source and view point at arbitrary distances, but differ in level of accuracy. As a consequence these alternative evaluation methods do impose restrictions on the topology of patches and light sources. However, generally, the limitations imposed by these alternative shading methods are much more liberal than the limitations on patch size imposed by the geometry. The most economic evaluation method we present can incrementally compute the colour intensity along a scanline by two additions per pixel. The methods presented are generally applicable and can easily be implemented in hardware.

A spatial metric for adapting the level of detail in a modelled object to achieve a convincing degree of realism on a display is formulated and illustrated with a simple implementation. This spatial metric is designed to be of most benefit to animations of natural environments. The metric can operate with a wide range of different representations: the essential requirement being that an abstract data structure with hierarchical levels of detail is formulated. Such models are most easily implemented with procedural recursive representations, such as fractals. The actor/message passing approach to modelling animation is adopted as being most appropriate and intuitive when simulating the objects and events of the natural environment. This object-oriented programming method also gives a uniform abstract interface to differing data representations. A stick figure, which has a non-uniform hierarchical structure, was chosen for the first implementation. This prototype was implemented in Smalltalk which had to be extended to include a part-whole (assembly-subassembly) hierarchy. The need to extend the metric to include temporal (dynamic) trade-offs is discussed.