Journal of Visual Languages and Computing最新文献

Graph sampling, simplying the networks while preserving primary graph characteristics, provides a convenient means for exploring large network. During the last few years a variety of graph sampling algorithms have been proposed, and the evaluation and comparison of the algorithms has witnessed a growing interest. Although different tests have been conducted, an important aspect of graph sampling, namely, uncertainty in graph sampling, has been ignored so far. Additionally, existing studies mainly rely on simple statistical analysis and a few relatively small datasets. They may not be applicable to other more complicated graphs with much larger numbers of nodes and edges. Furthermore, while graph clustering is becoming increasingly important, it is still unknown how different sampling algorithms and their associated uncertainty can impact the subsequent graph analysis, such as graph clustering. In this work, we propose an efficient visual analytics framework for measuring the uncertainty from different graph sampling methods and quantifying the influence of the uncertainty in general graph analysis procedures. A spreadsheet-style visualization with rich user interactions is presented to facilitate visual comparison and analysis of multiple graph sampling algorithms. Our framework helps users gain a better understanding of the graph sampling methods in producing uncertainty information. The framework also makes it possible for users to quickly evaluate graph sampling algorithms and select the most appropriate one for their applications.

Nonprofessional end user programs have increased remarkably in volume and diversity. However, for such programs to be usable and reliable, their creators should be familiar with software engineering practices that are typically not part of their range of competence and source of enjoyment. While the expansion of computational thinking acquisition (CTA) initiatives at schools and the availability of improved programming environments have contributed to facilitate the learners’ coding tasks, much less has been done to facilitate the acquisition of software quality notions. This paper reports on a Brazilian CTA program guided by semiotic principles and describes a study of how the technology used in it prefigures elements of software engineering in the participants’ programs created with AgentSheets. Our research contributions touch on the semiotic potential of CTA infrastructures and on associated pedagogical considerations for expanding CTA programs with software engineering basics. We also propose items for an interdisciplinary research agenda.

The search for ways to empower end users in activities such as programming and application customization has been subject of great effort among the research community, leading to the development of EUD environments, proper for end user’s activities. Among such environments there are the ones that have multiple layers of (distinct) users, consequently allowing multiple customizations. As an example, we have the Virtual Learning Environments (VLEs), with focus on education. In the particular case of VLEs, we are interested in verifying the discourse continuity after multiple customizations by many users, looking at how it impacts on teacher’s self-expression at the end of this chain, and how this expression is perceived by the students while interacting with the product of their teacher’s effort. This is part of a qualitative and descriptive evaluation with theoretical fundamentals on the Semiotic Engineering theory, the self-expression phenomenon, and end-user development practices. We have conducted three studies using Moodle as the VLE of choice. The first one identified three ways by which teachers practice self-expression via Moodle: through written language, interface customization, and expression through content, and Study 2 revealed that students perceive these same ways of expression. Finally, the inspections and the analyses of the interviews and questionnaires applied during Study 3 have confirmed these results, even after many customizations. That is, the teacher’s self (e.g., personality) is present and recognizable via interface. By taking EUD under the perspective of the Semiotic Engineering theory and self-expression, we were able to study the metacommunication intrinsic to multilevel customization software such as Moodle.

In research on Virtual Learning Environments (VLEs), it has been shown that teachers often do not explore VLEs to their full potential and only adopt a limited set of the available tools. In this article, we approach teachers’ design of VLE learning activities as end user development. We describe a study of Toledo, a virtual learning environment used across several higher education institutions in Belgium. Using a combination of a semiotic, multimodal analysis and an in-depth user study with 24 respondents, we provide a detailed account of how teachers appropriate the learning environment to suit their needs. Combining the insights from the semiotic investigation and the user research, we analyze how user appropriations can be explained as practices emerging from both how the platform communicates, and contextual factors. The study showed that some teachers design very specific learning activities using the VLE - not by using the dedicated VLE tool, but by reinterpreting more generic tools. These appropriation tactics concentrate platform use in a limited number of tools, even when teachers do use more complex learning activities. These results have implications for the design of VLEs: rather than offering a wide range of tools targeted at specific learning activities, VLEs could concentrate on providing basic communication tools that are open for appropriation.

The work presented in this paper aims at investigating how semiotic engineering and meta-design could be combined to support the development of socio-technical environments that enable End-User Development (EUD). In particular, I investigate the relationships existing between domain experts, playing the role of end-user developers, and meta-designers, mediated by EUD environments, and between end users and end-user developers mediated by EUD products. To this end, three case studies are considered, which belong to the recent research experience in EUD of the author. The case studies are concerned with three different application domains, namely physical prototyping of social products, accumulation and sharing of territory knowledge for first aid intervention, development of e-government services for the citizens of a municipality. The analysis is carried out both on the design process, by adopting a meta-design perspective, and on the product developed in each project, according to a semiotic engineering perspective. The analysis allows to shed light on the human and technical actors involved in EUD and on their communication processes, in order to understand which kinds of interaction visual languages and social conditions should be defined to encourage a continuous user-system co-evolution. As a result, the paper finally proposes some operative indications for the design of systems enabling EUD, which capitalize on semiotic engineering and meta-design ideas.

This paper presents the definition of a visual language and its implementation with the design of a visual interactive system for the collaborative management of Internet of Things (IoT) sensors (e.g., wearable fitness trackers, ambient sensors, fitness apps, nutrition apps, sleep trackers) for improving people's quality of life and promoting wellness awareness. The system, called SmartFit Rule Editor, is designed to be used by coaches and trainers of non-professional teams of athletes for monitoring and analyze fitness and wellness data streams and to support them in detecting relevant events and specifying rules for actions taking. Our research is framed under the scope of computer semiotics and semiotic engineering theories. This allows us to study how to support coaches and trainers as a community of domain experts – but not IT and IoT experts – to use elements of a visual language to indirectly manage physical devices and their data streams without the need to know technical specification of the devices, the apps, and the data. We apply a socio-technical approach to design being able to study the social and the technological aspects of the use of the Internet of Things ecosystem, considering them as closely interconnected and dependent. Such an approach underpins user-centered design and development methodologies in order to design the most suitable User eXperience according to users' culture, needs, context of use, and activity.

In this paper we discuss the concept of deictic sign as a component of the conceptual framework of Linguistics and Semiotics that can be added to Semiotic Inspection Method (SIM) in case the method is adapted to better approach digital games. Deictic signs should be here understood as signs that stablish an indexical relation with the objects they refer to, thus placing them in terms of space, time and person with a reference to the moment of communication though the interface. This paper analyzes such kind of signs in digital games; to do so, it discusses in detail the deictic aspects that SIM could not inspect when it was applied to the interfaces of the games Ingress, Kinectimals and Just Dance Now. As a result, we show that the category of deictic signs can be added to SIM when this method is adapted to systems that make explicit indexical references.

In this paper the authors propose a novel semiotic approach to the design of interactive systems and computational systems, grounded in the most recent contributions within the debate around semiotic theory and analysis. This approach, that is here called Semiotics of Configurations (SoC), is proposed for its analytic power in describing material artifacts and settings with a purposely a-conceptualistic stance. The resulting analysis informs a kind of design that is aimed at reproducing and supporting the programs of action detected in the use of artifacts, as this use is “abducted” from the physical and material form of the artifacts themselves and from the observation of how content is transformed within and across them. This approach to design, called immanent design, has inspired a platform for the user-driven development and use of electronic documents and forms in cooperative and organizational domains. The framework is illustrated with a case drawn from a study performed in the domain of hospital work.

Searching for relevant code in the local code base is a common activity during software maintenance. However, previous research indicates that 88% of manually composed search queries retrieve no relevant results. One reason that many searches fail is existing search tools’ dependence on string matching algorithms, which cannot find semantically related code. To solve this problem by helping developers compose better queries, researchers have proposed numerous query recommendation techniques, relying on a variety of dictionaries and algorithms. However, few of these techniques are empirically evaluated by usage data from real-world developers. To fill this gap, we designed a multi-recommendation system that relies on the cooperation between several query recommendation techniques. We implemented and deployed this recommendation system within the Sando code search tool and conducted a longitudinal field study. Our study shows that over 34% of all queries were adopted from recommendation; and recommended queries retrieved results 11% more often than manual queries.