This paper presents a Query-and-Relax System (QaRS) designed to facilitate the exploitation of large knowledge bases. QaRS proposes a graphical interface to construct a SPARQL query and use different cooperative answering techniques. The proposed cooperative techniques help users in finding alternative answers when their queries fail or do not return the expected number of answers. The present demonstration includes three main relaxation strategies: (1)- automatic where the system automatically relaxes the query based on similarity measures, (2)- manual where the user can specify the conditions that can or cannot be relaxed as well as the tolerance values and (3)- interactive where QaRS computes the causes of the query failure as a set of Minimal Failing Subqueries (MFSs )a nd then the user chooses the relaxation operators according to these MFSs.

Task analysis is a critical step in the design process of interactive systems. The large set of task models available today may lead to the assumption that this step is well supported. However, very few task models are tool-supported. And in this latter category, few of them are based on a clear semantics (in this article, the word semantics is used with the following definition: “the meaning of a word, phrase, sentence, or text” from Compact Oxford English Dictionary®). This paper focuses on tool-supported task models and provides an assessment of the features that have been considered as essential in task modelling. It compares the different tool-supported methods, and evaluates the actual use of these features in K-MADe, a tool aimed at contributing to the incorporation of ergonomics into the design process of interactive systems through activity and task analysis. The originality of the K-MADe tool is to be based on a model whose expressive power lies on computable syntax while trying to be usable by every modelling knowledge designer. This facilitates task description and analysis, but also model query and the migration within software engineering models and software lifecycle steps. Evaluation results demonstrate the usefulness of an increased expressive power for task models, and their acceptance by users. They also enlighten some weaknesses in the K-MAD method and suggest further improvements.

SUIDT (Safe User Interface Design Tool) is a model-based system that allows building interactive systems with respect to the formal semantics of functional cores. It implements a complete cooperation between task models (abstract and concrete) with both the domain model and the presentation model, while ensuring the properties of the models. Last, it maintains all during the design cycle the links between every part of the system, even the functions of the functional core (the actual code).