A system for automatically evaluating the usability and accessibility of web sites by checking their HTML code against guidelines has been developed. All usability and accessibility guidelines are formally expressed in a XML-compliant specification language called Guideline Definition Language (GDL) so as to separate the evaluation engine from the evaluation logics (the guidelines). This separation enables managing guidelines (i.e., create, retrieve, update, and delete) without affecting the code of the evaluation engine. The evaluation engine is coupled to a reporting system that automatically generates one or many evaluation reports in a flexible way: adaptation for screen reading or for a printed report, sorting by page, by object, by guideline, by priority, or by severity of the detected problems. This paper focuses on the reporting system.
How to visualize datasets hierarchically structured is a basic issue in information visualization. Compared to the common diagrams based on the nodes-links paradigm (e.g. trees), the enclosure-based methods have shown high potential to represent simultaneously the structure of the hierarchy and the weight of nodes. In addition, these methods often support scalability up to sizes where trees become very complicated to understand. Several approaches belong to this class of visualization methods such as treemaps, ellimaps, circular treemaps or Voronoi treemaps. This paper focuses on the specific case of ellimaps in which the nodes are represented by ellipses nested one into each other. A controlled experiment has previously shown that the initial version of the ellimaps was efficient to support the perception of the dataset structure and was reasonably acceptable for the perception of the node weights. However it suffers from a major drawback in terms of display space occupation. We have tackled this issue and the paper proposes a new algorithm to draw ellimaps. It is based on successive distortions and relocations of the ellipses in order to occupy a larger proportion of the display space than the initial algorithm. A Monte-Carlo simulation has been used to evaluate the filling ratio of the display space in this new approach. The results show a significant improvement of this factor.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.