Similarity is a key property across two or more interactive systems. Indeed, interacting with similar systems can bring benefits (e.g., reduced learning efforts and training time) but may also raise issues (e.g., interference errors and higher cognitive load). Interactive systems may be similar, as they correspond to the same work and tasks performed with different underlying systems, such as the pilots’ tasks in the cockpit of an Airbus A320 and a Boeing 737. They may also be similar by design, as they belong to the same suite as, for instance, the Microsoft Office software suite, where several tools are designed to be used concurrently by the same users. Previous work on similarity has focused on the visual presentation of interactive applications, highlighting commonalities and differences in terms of layout, shape, colours and other features of the user interface. This paper proposes a systematic and formal approach to analyse and assess the similarity between several interactive systems, focusing on their behaviours. To this end, we propose a tool-supported process that exploits both interactive formal system behaviour models and user task models. These models are analysed with the help of formal tools (model checking) to identify commonalities and differences in their exhibited behaviours. Beyond, we compare the specific and generic behavioural properties of each model, which provide semantic and meaningful information about how similar they are and how they differ. The approach is applied to two similar critical command and control interactive systems for flight safety operations in the space domain.

Operators of critical systems (e.g., air traffic controllers, pilots in commercial aircraft, operators managing space vehicle launch…) must acquire specific knowledge before being granted permission to perform their tasks on the job. They acquire such knowledge by following a training program developed for the specific tasks they will be doing. The preparation of their training program requires identifying the knowledge they have to acquire, and in particular, the two main types of knowledge that are declarative knowledge (a set of concepts required to operate a system) and procedural knowledge (a set of tasks required to operate a system). Task analysis techniques were originally proposed for the purpose of identifying and describing the knowledge required by users to interact with a system. These techniques provide support to describe procedural knowledge in detail, and a few of them provide limited support to describe declarative knowledge. In this paper, we propose a model-based technique to exhaustively identify and describe declarative and procedural knowledge, as well as to couple the different types of models in order to ensure the full coverage and consistency of the identification of knowledge required to operate an interactive system. We present the results from the application of the technique on a case study in the space domain.

Designing new input devices and associated interaction techniques is a key contribution in order to increase the bandwidth between users and interactive applications. In the field of Human-Computer Interaction, research and development services in industry and research laboratories in universities have been, since the invention of the mouse and the graphical user interface, proposing multiple contributions including the integration of multiple input devices in multimodal interaction technique. Those contributions, most of the time, are presented as prototypes or demonstrators providing evidence of the bandwidth increase through user studies. Such contributions however, do not provide any support to software developers for integrating them in real-life systems. When done, this integration is performed in a craft manner, outside required software engineering good practice. This paper proposes a systematic process to integrate novel input devices and associated interaction techniques to better support users' work. It exploits most recent interactive systems architectural model and formal model-based approaches for interactive systems supporting verification and validation when required. The paper focusses on Frame-based input devices which support gesture-based interactions and movements recognition but also addresses their multimodal use. This engineering approach is demonstrated on an interactive application in the area of rehabilitation in healthcare where dependability of interactions and applications is as critical as their usability.

Training operators of complex interactive systems is a difficult task that involves multiple actors, requires specific competencies and may be extremely costly in terms of time and resources. For instance, an initial training has to be performed in order to bring operators to a desired level of declarative and procedural knowledge. A successful operator will be granted a qualification to operate the system that was used for (or targeted by) the training. However, depending on the nature and the diversity of the operations performed on a daily basis, this initial training may decay and some knowledge may become deprecated. Recurrent training needs to be organised on a regular basis in order to keep operators qualified for the work. Such training differs from initial training and requires taking into account information about how humans learn and forget, what has been performed by operators since last training and the expected required level of knowledge. Trainers need to encompass all this generic information (to all operators) and specific information (to each individual) to define both initial and recurrent training programs. One particularly cumbersome task is the gathering of what happened during operations for each operator in order to minimize recurrent training program to knowledge that might have been forgotten as it was not used in recent operations. We propose a tool-supported task-model approach fed by information of the real work of operators in order to identify complete, relevant and efficient training for operators. These contributions have been applied to the civil aviation domain demonstrating multiple induced benefits.