Interactive Systems. Design, Specification, and Verification

Frontmatter

EMU in the Car: Evaluating Multimodal Usability of a Satellite Navigation System

Abstract

The design and evaluation of multimodal systems has traditionally been a craft skill. There are some well established heuristics, guidelines and frameworks for assessing multimodal interactions, but no established methodologies that focus on the design of the interaction between user and system in context. In this paper, we present EMU, a systematic evaluation methodology for reasoning about the usability of an interactive system in terms of the modalities of interaction. We illustrate its application using an example of in-car navigation. EMU fills a niche in the repertoire of analytical evaluation approaches by focusing on the quality of interaction in terms of the modalities of interaction, how modalities are integrated, and where there may be interaction breakdowns due to modality clashes, synchronisation difficulties or distractions.

Ann Blandford, Paul Curzon, Joanne Hyde, George Papatzanis

Comparing Mixed Interactive Systems for Navigating 3D Environments in Museums

Abstract

This work aims at developing appropriate Mixed Interaction Systems (MIS) for navigating 3D environments in a science centre context. Due to the wide range and multi-disciplinary design aspects to consider in this context and the lack of expertise in terms of MIS and public context evaluation, designing and evaluating MIS is a complex task. Based on an integrated development process, which combines a design model and a user-testing, this paper presents the outcomes of the comparison of two MIS in terms of performance and satisfaction.

Emmanuel Dubois, Cédric Bach, Philippe Truillet

An Attentive Groupware Device to Mitigate Information Overload

Abstract

We propose an attentive device for synchronous groupware systems to mitigate information overload. The opportunity seeker device leverages the users’ natural alternation between doing individual work and attending to the group to dynamically manage the delivery timing and quantity of group awareness information that each user is exposed to. We describe how this device can be implemented on an electronic brainstorming tool and show its influence on the distribution of ideas to the users. Results from a laboratory experiment using this tool indicate that group performance increased 9.6% when compared to the immediate broadcast of ideas and a post-hoc analysis suggests that information overload was attenuated: users were subject to 44.1% less deliveries of ideas, which gave them 54.7% more uninterrupted time; users switched 18.8% faster from submitting an idea to start typing the next idea; and the time to write an idea was reduced by 16.3%.

Antonio Ferreira, Pedro Antunes

Multi-fidelity User Interface Specifications

Abstract

Specifying user interfaces consists in a fundamental activity in the user interface development life cycle as it informs the subsequent steps. Good quality specifications could lead to a user interface that satisfies the user’s needs. The user interface development life cycle typically involves multiple actors possessing all their own particular inputs of user interface artifacts expressed with their own formats, thus posing new constraints for integrating them into comprehensive and consistent specifications of a future user interface. This paper introduces a design technique where these actors can introduce their artifacts by sketching them in their respective input format so as to integrate them into one or multiple output formats. Each artifact can be introduced in a particular level of fidelity (ranging from low to high) and switched to an adjacent level of fidelity after appropriate refining. Refined artifacts are then captured in appropriate models stored in a model repository. In this way, co-evolutionary design of user interfaces is introduced, defined, and supported by a collaborative design tool allowing multiple inputs and multiple outputs. This design paradigm is exemplified on a case study and has been tested in an empirical study revealing how designers appreciate it.

Thomas Memmel, Jean Vanderdonckt, Harald Reiterer

HOPS: A Prototypical Specification Tool for Interactive Systems

Abstract

This article suggests higher-order processes as a formal framework to model interactive systems and supplies a corresponding prototypical specifi cation tool (HOPS). Processes and their components reflect the recursive nature of interaction. Each component is an independent process itself. Though higher-level processes specify the interaction between their components they do not fully control them. HOPS offers a unified description of behavioral and structural aspects. Structured sets of sub-processes (e.g. hierarchies) serve to represent specific domains of interest within a process. Operations are the smallest units for analyzing and designing behavior. However, they can be unfolded to processes and vice versa. This supports an understanding of interactive systems as open and nonmonotonic systems. Their composition/ decomposition may exhibit unpredictable behavior. It is shown that the approach follows the interaction paradigm more closely than existing modeling approaches in HCI. Possible usage scenarios are given.

Anke Dittmar, Toralf Hübner, Peter Forbrig

Systematic Analysis of Control Panel Interfaces Using Formal Tools

Abstract

The paper explores the role that formal modeling may play in aiding the visualization and implementation of usability requirements of a control panel. We propose that this form of analysis should become a systematic and routine aspect of the development of such interfaces. We use a notation for describing the interface that is convenient to use by software engineers, and describe a set of tools designed to make the process systematic and exhaustive.

J. Creissac Campos, M. D. Harrison

Investigating System Navigation Ergonomics through Model Verification

Abstract

This paper discusses the use of formal models in the process of investigating the ergonomics of the navigation component in interactive systems. The investigation is based upon model analysis and a set of navigation properties. The formalism employed on this work was Coloured Petri Nets. The paper illustrates how the set of ergonomic properties was mapped into the model properties with the support of the formalism tools and specific functions developed to support the interface designer during model analysis. The context chosen as the basis for discussion is the operation of automated systems in the electricity industry; and a case study is presented to illustrate the analysis.

Alexandre Scaico, Maria de F. Q. Vieira, Markson R. F. de Sousa, Charles Santoni

Tool Support for Representing Task Models, Dialog Models and User-Interface Specifications

Abstract

This paper focuses on the visualization of task models. Models in general can be presented in different ways. We focus on tool support for different editors working on the same instance of a task model.

D. Reichart, A. Dittmar, P. Forbrig, M. Wurdel

Towards a Library of Workflow User Interface Patterns

Abstract

A collection of user interface design patterns for workflow infor ma tion systems is presented. Each Workflow User Interface Pattern (WUIP) is characterized by properties expressed in the PLML markup language for expressing patterns and augmented by additional attributes and models at tached to the pattern: the abstract user interface and the corresponding task model. These models are specified in a User Interface Description Langua ge. All WUIPs are stored in a library and can be retrieved within a workflow editor that links each workflow pattern to its corresponding WUIP, thus giving rise to a user interface for each workflow pattern. The software then gathers these UIs and the ones corresponding to workflow tasks into a user interface flow, a new concept introduced for specifying the intertwining of interfaces used by workers and the workflow manager in a single workflow.

Josefina Guerrero García, Jean Vanderdonckt, Juan Manuel González Calleros, Marco Winckler

Specification and Verification of Multi-agent Systems Interaction Protocols Using a Combination of AUML and Event B

Abstract

In this paper, we present a specification and verification technique for interaction protocols in multi-agent systems using a combination of Agent Unified Modeling Language (AUML) and the Event B method. The objective is to improve the semi-formal representation of agents, their precedence relation and protocol states as well as the formal analysis of safety and liveliness. The interaction protocol is initially modeled using the AUML protocol diagram. Then, the resulting model is translated into Event B and enriched with required interaction protocols properties to be verified using a B powerful support tool: B4free. In this paper, we focus on the translation process of AUML protocol diagrams into Event B and we illustrate our technique by an example of multi-agent systems interaction protocol.

Leila Jemni Ben Ayed, Fatma Siala

Pattern Languages as Tool for Discount Usability Engineering

Abstract

Despite growing pattern collections in the field of Human-Computer Interaction (HCI), both on the Internet [1-3] and in books [4, 5], these collections have usability problems when being used by those software engineers, who lack expertise in human-centered design. In this paper we report on the development of a tool that is intended to improve accessibility and usability of HCI design patterns for engineers. We aim at a tool that is simple and safe to be used without expert knowledge. Such a tool can be used in what could be labeled “discount usability engineering”. A new type of HCI pattern language combined with a supportive tool is intended to overcome some of the gaps these engineers have in HCI-background.

Elbert-Jan Hennipman, Evert-Jan Oppelaar, Gerrit van der Veer

Cascading Dialog Modeling with UsiXML

Abstract

This paper discusses multi-level dialog specifications for user interfaces of multi-target interactive systems and it proposes a step-wise method that combines a transformational approach for model-to-model derivation and an interactive editing of dialog models for tailoring the derived models. This method provides a synthesis of existing solutions for dialog modeling using a XML-based User Interface Description Language, UsiXML, along with State WebCharts notation for expressing the dialog at a high level of abstraction. Our aim is to push forward the design and reuse of dialog specifications throughout several levels of abstraction ranging from task and domain models until the final user interface thanks to a mechanism based on cascading style sheets. In this way, it is expected that the dialog properties are not only inherited from one level to another but also are made much more reusable than in the past.

Marco Winckler, Jean Vanderdonckt, Adrian Stanciulescu, Francisco Trindade

Designing Graphical Elements for Cognitively Demanding Activities: An Account on Fine-Tuning for Colors

Abstract

Interactive systems evolve: during their lifetime, new functions are added, and hardware or software parts are changed, which can impact graphical rendering. Tools and methods to design, justify, and validate user interfaces at the level of graphical rendering are still lacking. This not only hinders the design process, but can also lead to misinterpretation from users. This article is an account of our work as designers of colors for graphical elements. Though a number of tools support such design activities, we found that they were not suited for designing the subtle but important details of an interface used in cognitively demanding activities. We report the problems we encountered and solved during three design tasks. We then infer implications for designing tools and methods suitable to such graphical design activities.

Gilles Tabart, Stéphane Conversy, Jean-Luc Vinot, Sylvie Athènes

Lightweight Coding of Structurally Varying Dialogs

Abstract

A non-language-specific technique is given for programming of user interface (UI) dialogs. It allows the model (application data) to be pure (containing no UI-specific code). It requires no writing of callbacks or event handler functions. It allows editing of arbitrary data structures, with dynamic structural variation. This is achieved with a paradigm in which the UI specification code need not overtly name or store objects. Object management is performed automatically, facilitated by an incremental control structure. Volume of source code is reduced by about an order of magnitude compared to common UI toolkits. It has been implemented several times and used extensively in industry.

Michael Dunlavey

ReWiRe: Designing Reactive Systems for Pervasive Environments

Abstract

The design of interactive software that populates an ambient space is a complex and ad-hoc process with traditional software development approaches. In an ambient space, important building blocks can be both physical objects within the user’s reach and software objects accessible from within that space. However, putting many heterogeneous resources together to create a single system mostly requires writing a large amount of glue code before such a system is operational. Besides, users all have their own needs and preferences to interact with various kinds of environments which often means that the system behavior should adapt to a specific context of use while the system is being used. In this paper we present a methodology to orchestrate resources on an abstract level and hence configure a pervasive computing environment. We use a semantic layer to model behavior and illustrate its use in an application.

Geert Vanderhulst, Kris Luyten, Karin Coninx

Toward Multi-disciplinary Model-Based (Re)Design of Sustainable User Interfaces

Abstract

This paper reports on our experience in using the MuiCSer process framework for the redesign of the user interface for operating an industrial digital printing system. MuiCSer is created to support the user-centered interface design of new and legacy systems by a multi-disciplinary team. The process framework is created to enhance increased flexibility, usability and sustainability of the designed user interfaces. Resulting user interfaces are decoupled from the application logic, but still help to maintain consistency with the available functionality even when this changes over time. This report focuses on the usage of the task model during the analysis of the current user interface, the creation of user interface prototypes at various fidelity levels and the still ongoing realization of a flexible user interface management system to support future changes of the deployed user interfaces.

Jan Van den Bergh, Mieke Haesen, Kris Luyten, Sofie Notelaers, Karin Coninx

A Model-Based Approach to Supporting Configuration in Ubiquitous Systems

Abstract

This paper presents an approach for representing, and providing computer support for, the configuration of interactive systems, particularly ubiquitous systems, that offers a flexible method for combining a wide range of configuration techniques. There are many existing techniques offering dynamic adaptation, ranging from fully automatic through context-sensitive to user-driven. We propose a model that unifies all of these techniques and offers a rich choice of ways of combining them, based on the concept of configuration possibilities, evaluation functions applicable to sets of these possibilities and approaches for parameterising the functions and combining the results. We present a concept demonstrator implementation of the model, designed for home care systems, and describe a set of use cases based on this prototype implementation that illustrate the power and flexibility of the approach.

Tony McBryan, Phil Gray

Exploiting Web Services and Model-Based User Interfaces for Multi-device Access to Home Applications

Abstract

This paper presents a method, and the corresponding software architecture and prototype implementation to generate multi-device user interfaces in the home domain. The approach is based on Web services and model-based user interface generation. In particular, it focuses on multi-device interfaces obtained starting with XML descriptions of home Web services, which are then mapped onto user interface logical descriptions, from which it is possible to then generate user interfaces adapted to the target devices. During use, the generated interfaces are able to communicate with the home Web services and can be dynamically updated to reflect changes in domestic appliances available and the associated state.

Giulio Mori, Fabio Paternò, Lucio Davide Spano

Resources for Situated Actions

Abstract

In recent years, advances in software tools have made it easier to analyze interactive system specifications, and the range of their possible behaviors. However, the effort involved in producing the specifications of the system is still substantial, and a difficulty exists regarding the specification of plausible behaviors on the part of the user. Recent trends in technology towards more mobile and distributed systems further exacerbates the issue, as contextual factors come in to play, and less structured, more opportunistic behavior on the part of the user makes purely task-based analysis difficult. In this paper we consider a resourced action approach to specification and analysis. In pursuing this approach we have two aims - firstly, to facilitate a resource-based analysis of user activity, allowing resources to be distributed across a number of artifacts, and secondly to consider within the analysis a wider range of plausible and opportunistic user behaviors without a heavy specification overhead, or requiring commitment to detailed user models.

Gavin Doherty, Jose Campos, Michael Harrison

An Architecture and a Formal Description Technique for the Design and Implementation of Reconfigurable User Interfaces

Abstract

This paper proposes an architecture that provides a means to handle failures of input and output devices. This handling is done by means of previously defined and designed configurations. According to the failure identified at runtime of the interactive system, the most appropriate configuration will be loaded and executed. Such reconfiguration aims at allowing operators to continue interacting with the interactive system even though part of the user interface hardware has failed. These types of problems arise in domains such as command and control systems where the operator is confronted with several display units and can use various combinations of input devices either in a mono-modal or in a multimodal manner.

David Navarre, Philippe Palanque, Jean-François Ladry, Sandra Basnyat

COMET(s), A Software Architecture Style and an Interactors Toolkit for Plastic User Interfaces

Abstract

Plasticity of User Interfaces (UIs) refers to the ability of UIs to withstand variations of context of use (<User, Platform, Environment>) while preserving usability. This paper presents COMET, a software architecture style for building task-based plastic interactors. COMET bridges the gap between two main approaches in plasticity: model-driven engineering and interactors toolkits. Interactors that are compliant to the COMET style are called COMETs. These COMETs are multi-rendering multi-technological interactors (WIMP and post-WIMP, Web and non Web as well as vocal). COMETs are extensible and controllable by the user (up until now the designer, in the future the end-user). The COMET architecture and the use of COMETs are illustrated on an executable prototype: a slide viewer called CamNote++.

Alexandre Demeure, Gaëlle Calvary, Karin Coninx

Executable Models for Human-Computer Interaction

Abstract

Model-based user interface development is grounded on the idea to utilize models at design time to derive user interfaces from the modeled information. There is however an increasing demand for user interfaces that adapt to the context of use at runtime. The shift from design time to runtime means, that different design decisions are postponed until runtime. Utilizing user interface models at runtime provides a possibility to utilize the same basis of information for these postponed decisions. The approach we are following goes even one step further. Instead of only postponing several design decisions, we aim at the utilization of stateful and executable models at runtime to completely express the user interaction and the user interface logic in a model-based way.

Marco Blumendorf, Grzegorz Lehmann, Sebastian Feuerstack, Sahin Albayrak

A Middleware for Seamless Use of Multiple Displays

Abstract

Current multi-display environments (MDEs) can be composed of displays with different characteristics (e.g. resolution, size) located in any position and at different angles. These heterogeneous arrangements present specific interface problems: it is difficult to provide meaningful transitions of cursors between displays; it is difficult for users to visualize information that is presented on oblique surfaces; and it is difficult to spread visual information over multiple displays. In this paper we present a middleware architecture designed to support a new kind of perspective-aware GUI that solves the aforementioned problems. Our interaction architecture combines distributed input and position tracking data to generate perspective-corrected output in each of the displays, allowing groups of users to manipulate existing applications from current operating systems across a large number of displays. To test our design we implemented a complex MDE prototype and measured different aspects of its performance.

Satoshi Sakurai, Yuichi Itoh, Yoshifumi Kitamura, Miguel A. Nacenta, Tokuo Yamaguchi, Sriram Subramanian, Fumio Kishino

Graphic Rendering Considered as a Compilation Chain

Abstract

Graphical rendering must be fast enough so as to avoid hindering the user perception/action loop. Traditionally, programmers interleave descriptions and optimizations to achieve such performances, thus compromising modularity. In this paper, we consider graphic rendering as a compilation chain: we designed a static and dynamic graphical compiler that enables a designer to clearly separate the description of an interactive scene from its implementation and optimization. In order to express dependencies during run-time, the compiler builds a dataflow that can handle user input and data. We successfully used this approach on both a WIMP application and on a demanding one in terms of computing power: description is completely separated from implementation and optimizations while performances are comparable to manually optimized applications.

Benjamin Tissoires, Stéphane Conversy

Towards Specifying Multimodal Collaborative User Interfaces: A Comparison of Collaboration Notations

Abstract

Interactive systems including multiple interaction devices and surfaces for supporting the collaboration of a group of co-located users are increasingly common in various domains. Nevertheless few collaborative and multimodal interface specification notations are proposed. As a first step towards a notation for specifying a design solution prior to its software design and development, we adopt an empirical approach. We applied and compared four existing notations for collaborative systems by considering a case study, namely, a system for supporting informal co-located collaboration in hospital work. This paper reports the conclusions from this empirical comparison.

Frédéric Jourde, Yann Laurillau, Alberto Moran, Laurence Nigay

Towards Characterizing Visualizations

Abstract

The ability to characterize visualizations would bring several benefits to the design process. It would help designers to assess their designs, reuse existing designs in new contexts, communicate with other designers and write compact and unambiguous specifications. The research described in this paper is an initial effort to develop a theory-driven approach to the characterization of visualizations. We examine the Card and Mackinlay characterization tool and we show its limitations when it comes to performing a complete characterization.

Christophe Hurter, Stéphane Conversy

Towards Usability Evaluation for Smart Appliance Ensembles

Abstract

Smart environments comprise users and devices to form ad-hoc an ensemble and assist the users to fulfill their tasks more efficiently and more conveniently. This introduces new challenges for usability evaluations. To cope with theses issues, we propose the application of task models. Following this approach the behavior of the users can be interpreted as a trace through the corresponding task model. We discuss our method of capturing, visualizing and analyzing traces through task models within smart environments. The paper provides the first results of a prototypical implementation.

Gregor Buchholz, Stefan Propp

Task Model Refinement with Meta Operators

Abstract

In model-based user interface (UI) development task models are successively refined into more detailed task specifications. To ensure that analysis information is correctly translated into requirements and design artifacts it is important to verify that for each transformation step the derived task model is a valid refinement of its base specification. In this paper we present a versatile refinement relation between task models based on the principle of mandatory scenario equivalence. Which scenarios are mandatory is determined by metaoperators. These operators are assigned to tasks by the requirements engineer depending on the role of the task model in the development lifecycle.

Maik Wurdel, Daniel Sinnig, Peter Forbrig

Utilizing Dynamic Executable Models for User Interface Development

Abstract

In this demonstration we present the Multi Access Service Platform (MASP), a model-based runtime architecture for user interface development based on the idea of dynamic executable models. Such models are self-contained and complete as they contain the static structure, the dynamic state information as well as the execution logic. Utilizing dynamic executable models allows us to implement a rapid prototyping approach and provide mechanisms for the extension of the UI modeling language of the MASP.

Grzegorz Lehmann, Marco Blumendorf, Sebastian Feuerstack, Sahin Albayrak

Backmatter