| User interface plasticity: model driven engineering to the limit! | | BIBAK | Full-Text | 1-8 | |
| Joëlle Coutaz | |||
| Ten years ago, I introduced the notion of user interface plasticity to
denote the capacity of user interfaces to adapt, or to be adapted, to the
context of use while preserving usability. The Model Driven Engineering (MDE)
approach, which was used for user interface generation since the early eighties
in HCI, has recently been revived to address this complex problem. Although MDE
has resulted in interesting and convincing results for conventional WIMP user
interfaces, it has not fully demonstrated its theoretical promises yet. In this
paper, we discuss how to push MDE to the limit in order to reconcile high-level
modeling techniques with low-level programming in order to go beyond WIMP user
interfaces. Keywords: dynamic service composition, model driven engineering (mde), run time
adaptation, service-oriented architecture (SOA), user interface adaptation,
user interface composition, user interface generation, user interface
plasticity | |||
| Bridging models and systems at runtime to build adaptive user interfaces | | BIBAK | Full-Text | 9-18 | |
| Marco Blumendorf; Grzegorz Lehmann; Sahin Albayrak | |||
| Adapting applications and user interfaces at runtime requires a deeper
understanding of the underlying design. Models formalize this design, express
the underlying concepts and make them accessible to machines. In our work we
utilize runtime models to reflect the state of the interactive system (its UI
respectively) and to change its underlying configuration. So called executable
models combine design information, runtime state, and execution logic. From the
perspective of adaptive UIs this allows the dynamic reconfiguration of UIs
according to design information and the current state of the application at
runtime. Dedicated elements of the model create a causal interconnection
between model and user interface and facilitate a continuous information
exchange between the two. This creates a feedback loop between model and UI
where external stimulations influence the model execution and where projections
to the outside allow the dynamic alteration of user interfaces. Keywords: adaptive user interfaces, executable models, model-based user interface
development, model-driven engineering | |||
| Software refactoring process for adaptive user-interface composition | | BIBAK | Full-Text | 19-28 | |
| Anthony Savidis; Constantine Stephanidis | |||
| Adaptive user-interface composition is the ability of a software system to:
(a) compose its user-interface at runtime according to a given deployment
profile; and (b) to possibly drop running components and activate better
alternatives in their place in response to deployment profile modifications.
While adaptive behavior has gained interest for a wide range of software
products and services, its support is very demanding requiring adoption of
user-interface architectural patterns from the early software design stages.
While previous research addressed the issue of engineering adaptive systems
from scratch, there is an important methodological gap since we lack processes
to reform existing non-adaptive systems towards adaptive behavior. We present a
stepwise transformation process of user-interface software by incrementally
upgrading relevant class structures towards adaptive composition by treating
adaptive behavior as a cross-cutting concern. All our refactoring examples have
emerged from real practice. Keywords: adaptive user interfaces, software engineering, software process, source
code refactoring | |||
| How assessing plasticity design choices can improve UI quality: a case study | | BIBAK | Full-Text | 29-34 | |
| Audrey Serna; Gaëlle Calvary; Dominique L. Scapin | |||
| In Human Computer Interaction, plasticity refers to the capacity of User
Interfaces (UIs) to withstand variations of context of use while preserving
quality in use. Frequently, insuring more or less smooth transition from one
context of use to the other (from the end-user perspective) is conducted ad
hoc. To support a more systematic approach for characterizing UI tuning in
terms of quality in use along context of use variations, we present an
exploratory study focused deliberately on platform aspects. The design process
of this particular case study is detailed and all design decisions have been
recorded in terms of their influence on UI ergonomic quality, using Ergonomic
Criteria. The interesting result is that most design choices when changing the
platform lead to the reexamination of the initial designs. Ongoing work is done
to support the insight that considering plasticity seems to help in explicitly
broadening UI design choices and sharpening the solution. Keywords: plasticity, quality in use, ui design | |||
| Using ensembles of decision trees to automate repetitive tasks in web applications | | BIBAK | Full-Text | 35-40 | |
| Zachary Bray; Per Ola Kristensson | |||
| Web applications such as web-based email, spreadsheets and form filling
applications have become ubiquitous. However, many of the tasks that users try
to accomplish with such web applications are highly repetitive. In this paper
we present the design of a system we have developed that learns and thereafter
automates users' repetitive tasks in web applications. Our system infers users'
intentions using an ensemble of decision trees. This enables it to handle
branching, generalization and recurrent changes of relative and absolute
positions. Our evaluation shows that our system converges to the correct
solution after 3-8 iterations when the pattern is noise-free, and after 3-14
iterations for a noise level between 5-35%. Keywords: end-user programming, programming by example | |||
| Xplain: an editor for building self-explanatory user interfaces by model-driven engineering | | BIBAK | Full-Text | 41-46 | |
| Alfonso García Frey; Gaëlle Calvary; Sophie Dupuy-Chesa | |||
| Modern User Interfaces (UI) must deal with the increasing complexity of
applications in terms of functionality as well as new properties as plasticity.
The plasticity of a UI denotes its capacity of adaptation to the context of use
while preserving its quality. The efforts in plasticity have focused on the
(meta) modeling of the UI, but the quality remains uncovered. This paper
describes an on-going research that studies a method to develop
Self-Explanatory User Interfaces as well as an editor that implements this
method. Self-explanation makes reference to the capacity of a UI to provide the
end-user with information about its rationale (which is the purpose of the UI),
its design rationale (why is the UI structured into this set of workspaces?,
what's the purpose of this button?), its current state (why is the menu
disabled?) as well as the evolution of the state (how can I enable this
feature?). Explanations are provided by embedded models. Keywords: design rationale, help, model transformation, model-driven engineering,
self-explanatory user interfaces, ui quality | |||
| Increasing the automation of a toolkit without reducing its abstraction and user-interface flexibility | | BIBAK | Full-Text | 47-56 | |
| Prasun Dewan | |||
| The apparent tradeoff between user-interface automation and abstraction and
user-interface flexibility can be overcome using two key ideas. (1) It is
possible to automate several common aspects of a user-interface without
controlling its appearance. (2) By following well established programming
principles, developers can provide user-interface tools with information needed
for such automation. These ideas are used in a new approach that assumes that
programmers (a) encapsulate the semantics of interactive applications in model
objects, (b) use consistent ways to relate signatures of related methods, (c)
define method preconditions, and (d) use annotations for documentation. It uses
these principles to automate (a) binding of input events to synchronous and
asynchronous invocation of model methods, (b) syntactic and semantic validation
of user input, (c) binding of model state to display state, (c) undo/redo, and
(d) dynamic enabling/disabling of display components. The result is an approach
for increasing the automation of UI toolkits without reducing their abstraction
and user-interface flexibility. Keywords: user interface tools, user interface tools, MVC, preconditions, undo, redo | |||
| User interface design by sketching: a complexity analysis of widget representations | | BIBAK | Full-Text | 57-66 | |
| Suzanne Kieffer; Adrien Coyette; Jean Vanderdonckt | |||
| User interface design by sketching, as well as other sketching activities,
typically involves sketching objects through representations that should
combine meaningfulness for the end users and easiness for the recognition
engines. To investigate this relationship, a multi-platform user interface
design tool has been developed that enables designers to sketch design ideas in
multiple levels of fidelity with multi-stroke gestures supporting widget
representations and commands. A usability analysis of these activities, as they
are submitted to a recognition engine, suggests that the level of fidelity, the
amount of constraints imposed on the representations, and the visual difference
of representations positively impact the sketching activity as a whole.
Implications for further sketch representations in user interface design and
beyond are provided based on usability guidelines. Keywords: level of fidelity, shape recognition, sketching, user interface design, user
interface prototyping | |||
| An automated routine for menu structure optimization | | BIBAK | Full-Text | 67-76 | |
| Mikhail V. Goubko; Alexander I. Danilenko | |||
| We propose an automated routine for hierarchical menu structure
optimization. A computer advice-giving system founded on the mathematical model
of menu navigation directs the designer-driven process of sequential
enhancement, while menu designer caters for the semantic quality of menu labels
and groupings used. The mathematical model employs the frequencies of
functions' usage and the estimates of navigation time delays to calculate the
average search time for the current and optimal menu structure, to show the
"bottleneck" panels of the current menu, and to suggest the direction of their
improvement. The model covers the variety of menu types and allows choosing the
best type to meet requirements of specific application or user category. The
approach is illustrated by the optimization of a mobile phone command menu. Keywords: depth vs. breadth, menu design automation, menu of mobile device,
menu-driven system, optimal hierarchy, usability | |||
| Sketched menu: a tabletop-menu technique for GUI object creation | | BIBAK | Full-Text | 77-86 | |
| Mohammed Belatar; François Coldefy | |||
| In this paper, we describe the Sketched Menu, a menu technique for launching
Graphical User Interface (GUI) objects in a tabletop interface. The Sketched
Menu enables the user to define interactively the shape, size, orientation, and
location of a new GUI object before it is launched. These parameters are
specified implicitly by the user via a shape drawing. The shape corresponds to
a simplified outline of the object. A menu for the given shape is launched at
the exact location of the drawing and the user can then select the desired
graphical object or application. A laboratory experiment was conducted to
compare this new menu technique with the traditional pop-up-menu approach. The
results show that the time to create an object and the positioning accuracy are
similar for the two techniques. There are two advantages to using the Sketched
Menu. Firstly, graphical discontinuities are avoided when adding objects to the
interface. Secondly, because the object appears exactly in the desired location
and orientation, it does not hide other graphical objects, thereby reducing
disruption to other users' tasks. Keywords: collocated collaboration, cscw, gui orientation, interaction technique, menu
technique, tabletop display | |||
| Magellan, an evolutionary system to foster user interface design creativity | | BIBAK | Full-Text | 87-92 | |
| Dimitri Masson; Alexandre Demeure; Gaelle Calvary | |||
| Fostering creativity in User Interface (UI) design is challenging for
innovation. This paper explores the combination of model-based approaches and
interactive genetic algorithms to foster the exploration of the design space. A
user task model is given in input. Magellan produces sketches of UIs that aim
at inspiring the designer. Later on, appropriate tools may be used to tune the
right design into the design right. Magellan is a proof of concept that
deserves further exploration. Currently it is implemented using COMETs but it
is not dependent of this technology. Keywords: creativity, interactive genetic algorithm, Magellan, model-based user
interface design | |||
| MoPeDT: features and evaluation of a user-centred prototyping tool | | BIBAK | Full-Text | 93-102 | |
| Karin Leichtenstern; Elisabeth André | |||
| User-Centred Prototyping (UCP) tools are expected to support interface
developers in order to more efficiently, effectively and satisfactorily design,
evaluate and analyse user-friendly products by an all-in-one tool solution. We
developed such a UCP tool called MoPeDT that supports the user-centred
development of interactive evolutionary prototypes for mobile phones in the
context of the Internet of Things. In this paper we address our tool features
for the design, evaluation and analysis phase that mostly base on meaningful
features from related tools. Additionally, we cover potential enhancements to
former UCP tools in order to support interface developers with a wide-ranging
playground to investigate the user's behaviour and preferences. The paper also
describes MoPeDT's evaluation with 20 students over one month that investigated
the interface developer's efficiency, effectiveness and satisfaction when
applying our UCP tool. As an outcome of this study we describe potential
benefits and problems that might be of interest to other developers of UCP
tools. Keywords: evolutionary prototypes, internet of things, mobile phones, pervasive
interface, user-centred prototyping tool | |||
| Digisketch: taming Anoto technology on LCDs | | BIBAK | Full-Text | 103-108 | |
| Ramon Linus Hofer; Andreas Kunz | |||
| The Anoto technology uses a non-repetitive pattern printed on paper to
enable a camera-equipped pen to locate its absolute position on that pattern.
This technology is also used on projection screens to create large-sized
interactive areas, but suffers from the drawbacks such as shadow casting or
space requirements. Up to now, no implementation exists that enables a tracking
on LC-displays using the Anoto technology. Thus, we introduce Digisketch, which
uses special films that can be applied to LC-displays, to back and front
projections, or to glass, allowing pattern recognition for the pen's camera.
After describing the technical development of a prototype, we compare this new
possibility of using Anoto compatible surfaces with other traditional tracking
systems for LC-screens. Keywords: Anoto, LCD, optical tracking, pattern recognition, pen tracking, user study | |||
| WebWOZ: a wizard of oz prototyping framework | | BIBAK | Full-Text | 109-114 | |
| Stephan Schlögl; Gavin Doherty; Nikiforos Karamanis; Saturnino Luz | |||
| Language Technology (LT) based applications become more popular as
technology improves. Prototyping early in the design process is critical for
the development of high quality applications. It is difficult, however, to do
low-fidelity prototyping (e.g. paper prototyping) of applications based on LT.
One technique that has been used for this kind of prototyping is Wizard of Oz
(WOZ). However, this generally involves the development of one-off user and
wizard interfaces. A tool that facilitates the flexible integration of LT
components into WOZ experiments is desirable. In this paper we explore the
requirements for such a tool, drawing from the literature and a first WOZ
experiment in which different wizards were observed and their behaviour was
analysed. Keywords: language technology, prototyping, wizard of oz | |||
| Improving modularity and usability of interactive systems with Malai | | BIBAK | Full-Text | 115-124 | |
| Arnaud Blouin; Olivier Beaudoux | |||
| In this paper we present Malai, a model-based user interface development
environment. Malai is dedicated to the conception of post-WIMP (Window, Icon,
Menu, Pointing device) interactive systems. Malai aims at gathering together
principles from Norman's action model, instrumental interaction, direct
manipulation, the interactor concept and the DPI model (Documents,
Presentations, Instruments). It completes works on data manipulation techniques
used to link source data to user interfaces. We show how Malai can improve
modularity and usability of interactive systems by considering actions,
interactions and instruments as reusable first-class objects. Malai has been
successfully used for the development of several post-WIMP interactive systems.
We introduce each Malai component using the same example: a vector graphics
editor. Keywords: action, instrument, interaction, interactive system, MDE, user interface | |||
| COMM notation for specifying collaborative and multimodal interactive systems | | BIBAK | Full-Text | 125-134 | |
| Frédéric Jourde; Yann Laurillau; Laurence Nigay | |||
| Multi-user multimodal interactive systems involve multiple users that can
use multiple interaction modalities. Although multi-user multimodal systems are
becoming more prevalent (especially multimodal systems involving multitouch
surfaces), their design is still ad-hoc without properly keeping track of the
design process. Addressing this issue of lack of design tools for multi-user
multimodal systems, we present the COMM (Collaborative and MultiModal) notation
and its on-line editor for specifying multi-user multimodal interactive
systems. Extending the CTT notation, the salient features of the COMM notation
include the concepts of interactive role and modal task as well as a refinement
of the temporal operators applied to tasks using the Allen relationships. A
multimodal military command post for the control of unmanned aerial vehicles
(UAV) by two operators is used to illustrate the discussion. Keywords: groupware, multimodal interaction, specification notation | |||
| Representations for an iterative resource-based design approach | | BIBAK | Full-Text | 135-144 | |
| Anke Dittmar; Michael D. Harrison | |||
| This paper describes how the HOPS notation can be used to support Human
Centered Design. It discusses the role of the notation in providing multiple
design viewpoints. It demonstrates how the HOPS tool can be used to animate
these viewpoints. Finally, HOPS is used to specify how the system provides
information resources for user action. This approach to specifying plausible
user behavior is contrasted with a task based approach. The HOPS based design
techniques are illustrated through a process control example. Keywords: human centered design, task representation, viewpoints | |||
| User interface model discovery: towards a generic approach | | BIBAK | Full-Text | 145-154 | |
| Andy Gimblett; Harold Thimbleby | |||
| UI model discovery is a lightweight formal method in which a model of an
interactive system is automatically discovered by exploring the system's state
space, simulating the actions of a user; such models are then amenable to
automatic analysis targetting structural usability concerns. This paper
specifies UI model discovery in some detail, providing a formal, generic and
language-neutral API and discovery algorithm. The technique has been
implemented in prototype systems on several programming platforms, yielding
valuable usability insights. The API described here supports further
development of these ideas in a systematic manner. Keywords: discovery tools, interaction programming, reverse engineering, structural
usability | |||
| Taxonomy proposal for the description of accidents and incidents in the electrical systems operation | | BIBAK | Full-Text | 155-164 | |
| Daniel Scherer; Raffael C. da Costa; Joálison G. Barbosa; Maria de Fátima Q. Vieira | |||
| Documenting accidents and incidents in a clear, precise and unambiguous way
is essential to ground the error study and to propose preventive measures.
Research in the field of Human Error has yielded many taxonomies and
categorizations of errors which are used by companies when analyzing and
reporting on accidents and incidents. However, there are difficulties regarding
the appropriateness of the terms as applied to a company's specific context,
since taxonomies tend to be specific. Moreover, the lack of a clear
organization and the adoption of concepts which are not universal among users
with different background render their taxonomy's use rather difficult. This
paper proposes a taxonomy and an associated supporting tool for describing
accidents and incidents in the operation of electrical systems. The proposed
taxonomy addresses the concepts and the terms related to the causes of error as
well as concepts related to the user cognitive processes that led to the error. Keywords: human error, taxonomy, user's activities | |||
| Beyond modelling: an integrated environment supporting co-execution of tasks and systems models | | BIBAK | Full-Text | 165-174 | |
| Eric Barboni; Jean-François Ladry; David Navarre; Philippe Palanque; Marco Winckler | |||
| This paper focuses on the articulations of task models and system models.
Tasks models are meant to be used by human factor specialists whilst system
models are supposed to be produced by software engineers. However, tasks models
and systems models represent two different views on how users interacting with
a computing system to reach a goal. This paper presents an integration
framework aiming to take full advantage of task models and system models that
have been developed initially in a separated manner and how these two views can
be integrated at the model level and additionally at the tool level. The main
contribution of the paper lies in the definition of such integration at the
tool level to be used at runtime (while the user is operating the system).
Indeed, thanks to this integration contextual help can be offered to the users
supporting the construction of the mental bridge between what they have to do
(defined in the tasks model) and what the interactive system allows (defined in
the system model). The approach, the tools and the integration are presented on
a case study of a Weather Radar System (WXR) embedded in aircraft cockpits. Keywords: models integration, task and systems models, tool support | |||
| Developing usability studies via formal models of UIs | | BIBAK | Full-Text | 175-180 | |
| Judy Bowen; Steve Reeves | |||
| Developing usability studies to evaluate software is a task requiring a wide
variety of skills. For software developers who are not used to taking a
user-centred approach to development it is often easier and more convenient to
dismiss the use of user evaluation as too time-consuming or too hard. This is
even more likely to be the case for developers who take a formal approach to
software development, which is generally not focused on interface or usability
concerns. In this paper we present an early investigation into the use of
formal models of user interface designs as the basis for designing software
evaluation studies. We have undertaken a comparison study to find out whether a
useful study can be derived in this way and whether or not further
investigation into this is worthwhile, and we present the results here. Keywords: formal methods, software evaluation, ui design, ui models, usability studies | |||
| The GUISurfer tool: towards a language independent approach to reverse engineering GUI code | | BIBAK | Full-Text | 181-186 | |
| João Carlos Silva; Carlos C. Silva; Rui D. Gonçalo; João Saraiva; José Creissac Campos | |||
| Graphical user interfaces (GUIs) are critical components of today's
software. Developers are dedicating a larger portion of code to implementing
them. Given their increased importance, correctness of GUIs code is becoming
essential. This paper describes the latest results in the development of
GUISurfer, a tool to reverse engineer the GUI layer of interactive computing
systems. The ultimate goal of the tool is to enable analysis of interactive
system from source code. Keywords: analysis, graphical user interfaces, source code | |||
| Feasible database querying using a visual end-user approach | | BIBAK | Full-Text | 187-192 | |
| Clemente Rafael Borges; José Antonio Macías | |||
| Querying databases is a common daily task carried out by a great deal of
end-users who do not have specific skills in SQL language. Today, most of the
database interaction is achieved by means of query interfaces provided by the
database environment. However, most of these interfaces suffer from expressive
limitations, since they are mostly based on metaphors that drastically restrict
the expressiveness of the SQL language that is generated and executed in the
background. In this paper, we present a visual interaction language and tool
focused on easily querying databases by end-users. We make no assumption on the
level of the user's experience with query languages, as our visual metaphor is
intended for querying databases by unskilled end-users and also leveraging the
restriction on the expressiveness of the queries created by them. We also
report on some late braking results obtained by an experiment carried out with
real users. Keywords: data warehouse, end-user development (EUD), usability, visual interfaces,
web-based interaction | |||
| Letras: an architecture and framework for ubiquitous pen-and-paper interaction | | BIBAK | Full-Text | 193-198 | |
| Felix Heinrichs; Jürgen Steimle; Daniel Schreiber; Max Mühlhäuser | |||
| Paper remains a prevalent medium in mobile usage contexts due to its
inherent flexibility and robustness. Mobile computing solutions begin to
provide powerful and convenient functionality, while the gap between paper
documents and digital applications remains unbridged in mobile settings.
Current toolkits do not offer adequate support for development of mobile
pen-and-paper based applications, as they lack support for important mobile
characteristics of real paper: user mobility and document mobility. To overcome
their limitations, we present a novel generic architecture, along with its
reference implementation Letras, a light-weight, freely available
infrastructure to develop pen-and-paper based applications in mobile settings. Keywords: anoto, development tools/toolkits/programming environments, digital pen,
handheld devices and mobile computing, pen and tactile input, ubiquitous
computing/smart environments | |||
| Adapting existing applications to support new interaction technologies: technical and usability issues | | BIBAK | Full-Text | 199-204 | |
| Darren Andreychuk; Yaser Ghanam; Frank Maurer | |||
| Engineering interactive systems for use on emerging technologies such as
touch-enabled devices and horizontal displays is not straightforward. Firstly,
the migration process of a system from an old hardware platform to new
multi-touch displays is challenging. Issues pertaining to scaling, orientation,
new input mechanisms, novel interaction techniques and different SDKs need to
be examined. Secondly, even after we manage to understand and resolve these
issues, we need to find effective ways to migrate applications and maintain
them.
This paper contributes a thorough analysis of the technical and usability issues that need to be considered when migrating systems to different touch-enabled technologies including vertical and horizontal displays. Keywords: adaptability, evolution, surfaces | |||
| Semantic awareness through computer vision | | BIBAK | Full-Text | 205-210 | |
| Sami Benzaid; Prasun Dewan | |||
| An important application of multi-user interfaces is distributed
presentations. In such presentations, the presenters do not have the ability to
assess the real-time level-of-interest of the audience through observation, as
they would in real lecture rooms. Using vision techniques, we aim to introduce
a path that, if followed, could potentially lead to a robust technique that
provides this information in such a presentation in real time. Keywords: cscw, distributed presentation, semantic awareness | |||
| Model engineering for model-driven engineering | | BIBAK | Full-Text | 211-212 | |
| Axel van Lamsweerde | |||
| The effectiveness of model-driven engineering relies on our ability to build
high-quality models. This task is intrinsically difficult. We need to produce
sufficiently complete, adequate, consistent, and well-structured models from
incomplete, imprecise, and sparse material originating from multiple, often
conflicting sources. The system we need to consider in the early stages
comprises software and environment components including people and devices.
Such models should integrate the intentional, structural, functional, and behavioral facets of the system being developed. Rigorous techniques are needed for model construction, analysis, and evolution. They should support early and incremental reasoning about partial models for a variety of purposes, including satisfaction arguments, property checks, animations, the evaluation of alternative options, the analysis of risks, threats and conflicts, and traceability management. The tension between technical precision and practical applicability calls for a suitable mix of heuristic, deductive, and inductive forms of reasoning on a suitable mix of declarative and operational models. Formal techniques should be deployed only when and where needed, and kept hidden wherever possible. The talk will provide a retrospective account of our research efforts and practical experience along this route, including recent progress in model engineering for safety-critical medical workflows. Problem-oriented abstractions, analyzable models, and constructive techniques are pervasive concerns. Keywords: model-driven engineering, requirements, system design | |||
| Collaboratively maintaining semantic consistency of heterogeneous concepts towards a common concept set | | BIBAK | Full-Text | 213-218 | |
| Jingzhi Guo; Iok Ham Lam; Chun Chan; Guangyi Xiao | |||
| In e-business, creating a common concept set for business integration,
interoperation and interaction has to consider the heterogeneity reality of
different interpretations from multiple concept providers. Maintaining semantic
consistency between multiple concept providers is a difficult problem. To solve
this problem, this paper first reviewed the existing technologies of
collaborative editing systems and consistency maintenance in the areas of both
CSCW and e-business. Based on the discussion of existing technologies, it then
proposes a novel CHCES approach, which divides a collaborative editing system
into two layers in topology and introduces four strategies to edit common
concepts between the two layers. A set of operations is designed, which
demonstrates the solution. Keywords: collaborative editing, electronic business, semantic consistency maintenance | |||
| Exploiting web service annotations in model-based user interface development | | BIBAK | Full-Text | 219-224 | |
| Fabio Paternò; Carmen Santoro; Lucio Davide Spano | |||
| In this paper we present a method and the associated tool support able to
exploit the content of Web service annotations in model-based user interface
design and development. We also show an example application of the proposed
approach. Keywords: annotations, model-based user interface design, task models., web services | |||
| Mixed-focus collaboration without compromising individual or group work | | BIBAK | Full-Text | 225-234 | |
| Prasun Dewan; Puneet Agarwal; Gautam Shroff; Rajesh Hegde | |||
| In mixed-focus collaboration, users "continuously" switch between
"individual" and "group" work. We have developed a new two-person interaction
mechanism, coupled tele-desktops, that is, arguably, not biased towards
individual or group work. We evaluate this mechanism, and the general idea of
mixed-focus collaboration, using a new quantitative framework consisting of (a)
a set of precisely-defined coupling modes determining the extent of individual
and group work, and (b) the times spent in, durations of, and number of
transitions among these modes. We describe a new visualization scheme for
compactly displaying these metrics in an individual collaborative session. We
use this framework to characterize about forty six person hours of use of
coupled tele-desktops, most of which involved collaborative use of a UI
builder. Our results include (a) quantitative motivation for coupled
tele-desktops, and (b) several new quantitative observations, and
quantification of several earlier qualitative observations regarding
mixed-focus collaboration. Keywords: awareness, coupling, side-by-side collaboration | |||
| Virtual collaborative environments with distributed multitouch support | | BIBAK | Full-Text | 235-240 | |
| Oscar Ardaiz; Ernesto Arroyo; Valeria Righi; Oriol Galimany; Josep Blat | |||
| In this paper, we present a new application framework aimed to support
distributed synchronous collaboration using multitouch interaction. The
framework supports 2D and 3D virtual workspaces that enable two or more users
to collaboratively or cooperatively manipulate shared objects with multitouch
interfaces. We present two applications developed with the aim to explore 2D/3D
immersive collaborative environments with multitouch interaction. We also
present our experience and preliminary results in designing, developing and
integrating these applications on educational settings. Keywords: distributed virtual environment, multitouch interaction, remote
collaboration | |||
| Aligning business goals and user goals by engineering hedonic quality | | BIBAK | Full-Text | 241-250 | |
| Kerstin Klöckner; Kirstin Kohler; Daniel Kerkow; Sabine Niebuhr; Claudia Nass | |||
| The following paper deals with quality properties that extend the
traditional understanding of usability with its focus on the pragmatic aspects
like efficiency and effectiveness on task performance in the context of
business applications. The contribution of the approach is tow folded. First:
We show how psychological theories about motivation and creativity can bridge
the gap between business goals and users' goals and attitude with interaction
design. We introduce an engineering approach that allows to deliberately design
for fun/joy in a given business context. Second: We show how to reuse the
experience from former or other projects by describing the interaction design
as pattern candidates. This approach has been applied successfully many times
and we elaborate it in a case study conducted for one of our clients, including
an empirical evaluation that shows an improved working behavior and increased
user acceptance of the software. Keywords: business goals, fun-of-use, hedonic quality, interaction pattern,
joy-of-use, user experience, user interface engineering | |||
| Activity-centric support for weakly-structured business processes | | BIBAK | Full-Text | 251-260 | |
| Benedikt Schmidt; Todor Stoitsev; Max Mühlhäuser | |||
| Knowledge-intensive tasks are a blind spot for business process management
systems, as these tasks are executed in an unsupervised, highly individual
manner. Hence, individual experience is not disseminated and task execution
largely depends on implicit knowledge.
In this paper we present a framework, realizing situation-specific and personalized task execution support for knowledge-intensive tasks in business processes. As a core concept we suggest activity scheme: a structure capturing a probabilistic task execution model. Activity schemes seamlessly integrate the organizational business process with the individual task execution process based on personalization and generalization of user interactions in the working applications. Keywords: human-computer interaction, knowledge work support, task execution support | |||
| Service discovery supported by task models | | BIBAK | Full-Text | 261-266 | |
| Kyriakos Kritikos; Fabio Paternò | |||
| We propose an approach that takes as input a task model, which includes the
user's view of the interactive system, and automatically discovers a set of
categorized and ranked service descriptions for each system task of the model.
In this way, a set of service operations can be used to implement an
application's part or whole functionality so that its development time is
significantly reduced. Keywords: interactive application design, semantic service discovery, service
front-ends, term to ontology concept matching | |||
| Design pattern TRABING: touchscreen-based input technique for people affected by intention tremor | | BIBAK | Full-Text | 267-272 | |
| Alexander Mertens; Nicole Jochems; Christopher M. Schlick; Daniel Dünnebacke; Jan Henrik Dornberg | |||
| Tremor patients are frequently facing problems when interacting with IT
systems and services. They do not reach the same levels of input efficiency and
easily become unhappy with a technology they do not perceive as a general
asset. Cases of Intention tremor show a significant comparative rise in
inaccurate movement towards a real button or virtual buttons on touch screens,
as this particular tremor increases its symptoms when approaching a desired
physical target. People suffering from this specific tremor have been
identified as the target group. This group has been closely investigated and
thus, a new input procedure has been developed which may be used on standard
touch screens. The new technique enables users, accordingly tremor patients, to
fully operate IT-based systems and therefore possess full control over input.
Deviations caused by the tremor are compensated with a continuous movement
instead of a single targeted move which remains the most difficult task to the
user. Also, the screen surface will present a frictional resistance, which
significantly hinders tremor symptoms. Input can be identified by the computer
system with high accuracy, by means of special heuristics, which support
barrier free access beyond the target group. Keywords: ambient assisted living (AAL), design pattern, human-computer interaction
(hci), touchscreen, tremor | |||
| Model-driven GUI & interaction design using emulation | | BIBAK | Full-Text | 273-278 | |
| Annika Hinze; Judy Bowen; Yuting Wang; Robi Malik | |||
| This paper introduces a model-driven emulator for the interaction and GUI
design of complex interacting systems. It allows systems that are engineered
using formal methods and modelling to be tested with users before the final
implementation. The user interface requirements are also specified in a formal
model, which can be tested manually and automatically as required. Keywords: formal modelling, gui, interaction design, mobile | |||
| Using the mobile application EDDY for gathering user information in the requirement analysis | | BIBAK | Full-Text | 279-284 | |
| Stephan Hammer; Karin Leichtenstern; Elisabeth André | |||
| The users' knowledge and requirements are important factors in the design of
products. To ensure the success of products designers and developers have to
get to know their target group users better. Over the years a lot of innovative
user centered design studies have been written. Many researchers believe that
these studies could be used by developers to help them in the process of
creating new products. This paper presents a framework called EDDY that aims at
facilitating the development of mobile applications for gathering various kinds
of data. Such a framework and applications based on it should be helpful for
the data collection during studies such as Cultural Probes and the Experience
Sampling Method. These approaches involve the users as the persons who collect
the required information themselves. In this paper we evaluate the advantages
of EDDY for such studies. We investigated whether there is a significant
advantage in using a mobile application for the documentation of a user's
everyday life instead of using a classical kit. Keywords: context-aware system, cultural probes, experience sampling method (ESM),
mobile phones, requirement analysis | |||
| History-based device graphical user-interfaces | | BIBAK | Full-Text | 285-290 | |
| Olufisayo Omojokun; Prasun Dewan | |||
| Due to limited screen space on mobile computers, device GUIs can span
multiple screens-requiring tedious scrolling and tabbing for commands.
History-based device GUIs can significantly reduce required space by only
presenting the commands a user typically needs based on the user's behavior
over a short training period. Moreover, history-based UIs and model-based UI
generation are symbiotic. Generation relieves programmers from the overhead of
logging and interpreting the interaction histories. Conversely, history-based
user-interaction noticeably lowers inherent UI generation time by omitting
unneeded commands. Keywords: devices, logging, mobile computing, model-based user-interface generation,
personalization, screen space, uims | |||
| Bridging the gap: empowering use cases with task models | | BIBAK | Full-Text | 291-296 | |
| Daniel Sinnig; Rabeb Mizouni; Ferhat Khendek | |||
| Use cases have become the standard for modeling functional requirements,
whereas task models are used to capture UI requirements. Despite recent
advances, software engineering (SE) and user interface (UI) design methods are
poorly integrated making it difficult for SE and UI teams to collaborate,
synchronize their efforts and avoid inconsistencies. To address these issues,
we propose an integrated development methodology for use cases and task models.
Both artifacts are used to specify software requirements, but emphasize two
different aspects in a complementary manner. The integration consists of using
CTT task models to iteratively enrich UI related steps in the use case model.
We demonstrate that such an approach allows for a clear separation of concerns
and therefore avoids potential inconsistencies between the two artifacts. Keywords: development methodology, task models, use cases, user interface development | |||
| UsabML: formalising the exchange of usability findings | | BIBAK | Full-Text | 297-302 | |
| Johannes Feiner; Keith Andrews; Elmar Krajnc | |||
| During the iterative development of interactive software, formative
evaluation is often performed to find and fix usability problems early on. The
output of a formative evaluation usually takes the form of a prioritised list
of usability findings, each finding typically consisting of a description of
the problem, how often it occurred, and sometimes a recommendation for a
possible solution.
Unfortunately, the valuable results of formative evaluations are usually collected into a written document. This makes it extremely difficult to automate the handling of usability findings. A more formalised, electronic format for the handover of usability findings would make much more sense. UsabML is a formalised structure for reporting usability findings expressed in XML. It allows usability experts and software engineers to import usability findings into bug (issue) tracking systems, to associate usability issues with parts of source code, and to track progress in fixing them. Keywords: issue tracking, software repositories, standard reporting format, usability
findings, xml | |||
| Seamless integration of heterogeneous UI components | | BIBAK | Full-Text | 303-308 | |
| Heiko Paulheim; Atila Erdogan | |||
| Component-based software engineering is a paradigm aiming at better ways to
reuse existing code and to distribute work across teams. Integrating UI
components developed with different technologies can be a difficult task which
can quickly can lead to code-tangling and loss of modularity. In this demo, we
present a prototype framework for integrating heterogeneous UI components,
using RDF and formal ontologies for unambiguous event and data exchange and
minimizing dependencies between integrated components. We will show an example
from the emergency management domain using components written in Java and Flex
and demonstrate tight, seamless integration, including dragging and dropping
objects from Java to Flex and vice versa. Keywords: component-based software, integration, ontologies, user interfaces | |||
| Development of context-adaptive applications on the basis of runtime user interface models | | BIBAK | Full-Text | 309-314 | |
| Grzegorz Lehmann; Marco Blumendorf; Sahin Albayrak | |||
| One of the challenges faced by developers of applications for smart
environments is the diversity of contexts of use. Applications in smart
environments must cope with continuously changing context of use, so the
developers need to prepare them for a possibly broad range of situations. Since
the developer has no access to all environments, in which her application will
be executed, it must be possible to simulate different environments and
evaluate the behavior of the application at design time. In our demonstration
the designer has the possibility to simulate and modify a runtime context model
and observe as her application adapts on the fly. In the underlying runtime
architecture applications, defined as sets of models, are adapted automatically
on the basis of the information held in the runtime context model. A visual
tool enables the user interface developer to access and modify the models at
any time and immediately observe the behavior of the application. Keywords: adaptive user interfaces, executable models, model-based user interface
development, model-driven engineering | |||
| A demonstration of the flexibility of widget generation | | BIBAK | Full-Text | 315-320 | |
| Prasun Dewan | |||
| Several user-interface tools have been developed that (semi) automatically
generate widgets for interacting with model objects. However, details of the
nature of the model-widget mapping and the range of widget compositions that
can be automatically created remain largely unpublished, and hence unknown.
Moreover, most of this work has considered flat models. Using a variety of
user-interfaces, which are proposed as benchmarks for evaluating widget
generation, this paper demonstrates and derives a flexible and (semi) automatic
algorithm for mapping between model and widget compositions. Keywords: benchmarks, inheritance, layout, MVC | |||
| Interactive model driven graphical user interface generation | | BIBAK | Full-Text | 321-324 | |
| David Raneburger | |||
| The current multitude of devices with different screen resolutions or
graphic toolkits requires different user interfaces (UIs) for the same
application. Model Driven UI Development solves this problem by transforming
one target device independent specification into several target device
dependent UIs. However, the established Model Driven Architecture (MDA)
transformation process is not flexible enough to fully support all requirements
of UI development. The vision of this thesis is to bridge the gap between the
capabilities of model driven software engineering and the requirements of UI
development. This work introduces an interactive model driven UI development
approach that gives the designer control over the UI during the development
process. Additional interactive support enables the designer to make informed
design decisions which will ultimately lead to more satisfying UIs. Keywords: interactive user interface generation, model driven, semi-automatic
customization | |||
| Understanding the influence of 3D virtual worlds on perceptions of 2D e-commerce websites | | BIBAK | Full-Text | 325-328 | |
| Minh Q. Tran | |||
| This PhD research aims to understand the influence of consumers' experiences
in 3D virtual worlds on their perceptions and expectations of 2D e-commerce
websites. Interviews are being conducted with consumers who have shopping
experiences in 3D and 2D environments. The contribution of this research will
be an understanding of user needs in e-commerce environments. This
understanding will be applied to develop e-commerce design guidelines in both
2D and 3D e-commerce environments. Keywords: 3d virtual worlds, design guidelines, e-commerce, user experience | |||
| Integrating end-user support and negotiations to specify requirements for context-based adaptations in a collaboration environment | | BIBAK | Full-Text | 329-332 | |
| Syed Sajid Hussain | |||
| Context-based adaptation reduces the overhead of work breakdown
identification and handling from end-users by automated system-initiated
adjustments of behavior of collaborative system. But this approach makes
adaptation awareness, understanding and revision difficult. We propose a
process model guiding the interaction among end-users when dealing with
context-based adaptations to avoid these problems. This model also empowers
end-users to add exceptions and to specify requirements to add, modify, or
delete adaptation policies as amendment requests. End-user negotiations are
conducted to remove conflicts because of conflicting views on adaptations and
to form consensus before an amendment request is implemented. Keywords: collaborative conflict management, contextual and situation-based
collaboration, end-user support, requirement engineering in collaboration
environments, socio technical information spaces | |||
| The fluid software metadata framework (FSM) | | BIBAK | Full-Text | 333-336 | |
| Johannes Feiner | |||
| The Fluid Software Metadata (FSM) framework is a dynamic and flexible
framework for software repository metadata generation and analysis. FSM aims to
improve the setup time for the mining, analysis, and interactive visualisation
of repository artefacts. FSM supports the integration of usability findings
through XML-based usability reports. Viewing usability issues side-by-side with
source code provides several advantages in holistic software development. Keywords: development tools, framework, metrics, software repositories, usability
issues, visualisation, web interface | |||
| A model- and pattern-based approach for development of user interfaces of interactive systems | | BIBAK | Full-Text | 337-340 | |
| Jürgen Engel | |||
| This paper introduces the subject of my PhD thesis, a framework for
pattern-based modeling, generation and usability evaluation of interactive
systems. It describes the structural aspects of HCI pattern languages and how
such languages and patterns for various modeling stages (e.g. task modeling)
and abstraction levels can be exploited to automate part of the software
development process for interactive applications. The main aspects and the
general functionality of the framework as well as the supported development
processes are discussed. Keywords: interactive system, model-driven development, pattern-based development,
software generation, user interface | |||
| Self-explanatory user interfaces by model-driven engineering | | BIBAK | Full-Text | 341-344 | |
| Alfonso García Frey | |||
| Modern User Interfaces (UI) must deal with the increasing complexity of
applications in terms of functionality as well as new properties as plasticity.
The plasticity of a UI denotes its capacity of adaptation to the context of use
preserving its quality. The efforts in plasticity have focused on the (meta)
modeling of the UI, but the quality remains uncovered. We suggest a method for
improving the quality of the UIs by providing explanations about the design of
the UI itself: this is, by the use of the Self-Explanation. Self-Explanatory
User Interfaces (SEUI) makes reference to the capacity of a UI to supply the
end-user with all the information on the rational of the UI, about its
constitution (for example, what is the purpose of this button?), its current
state (why is the menu disabled?) as well as its evolution (how can I enable
this feature?).
This thesis investigates the SEUI by Model Driven Engineering (MDE), where models are kept at run-time allowing the necessary techniques that maintain this link between design and execution. Keywords: design rationale, help, model transformation, model-driven engineering,
self-explanatory user interfaces, ui quality | |||
| The triad-based design of rich user interfaces for internet applications | | BIBAK | Full-Text | 345-348 | |
| Francisco Javier Martínez-Ruiz | |||
| Current trends in web development still are attached to the web page
paradigm. Nevertheless, new uses of already available technology and recent
development in terms of concepts, as the asynchronous communication, have
produced a new generation of web applications: Rich Internet Applications
(RIAs). These web applications tries to fulfill user expectations in terms of
usability, reliability, quality, maintainability and performance. In our work,
we are going to present a design methodology that pursued as goal describing
and developing User Interfaces of RIAs in a standardized way. Keywords: model driven engineering, rich internet applications, usixml., web
engineering | |||
| Towards an evolutionary framework for agile requirements elicitation | | BIBAK | Full-Text | 349-352 | |
| Sandra Kelly | |||
| Numerous reports document difficulties experienced with the development of
requirements in software projects. Specifically problems include: developers
have limited access to stakeholders, don't fully understand the problem domain
and as a consequence, requirements are not well understood. Agile Methods (AMs)
encourage stakeholder involvement throughout development however considerable
difficulty remains in accommodating continuous negotiation between multiple
diverse stakeholders in a given domain. This paper reports on progress to date
for developing an evolutionary framework to improve the facilitation of agile
requirements elicitation. A potential solution is offered and an initial study
indicates positive results. Keywords: agile methods (ams), elicitation, open space technology (OST), requirements,
scenarios | |||
| UI generation from task, domain and user models: the DB-USE approach | | BIBAK | Full-Text | 353-356 | |
| Vi Tran | |||
| Information Systems UI (User Interface) generation from declarative models
has been the focus of numerous and various approaches in the human computer
interaction community. Typically, the different approaches use the different
models based on their singular aspects. This paper proposes a new process that
combines the task, domain, and user models taken together to drive the
information system user interface design and code behind generation. To this
end, we propose a framework, i.e., a methodological process, a meta-model and a
software prototype called DB-USE. Keywords: automatic user interface generation, domain model, task model, user model | |||
| DOM tree estimation and computation: overview of a new web content adaptation system | | BIBAK | Full-Text | 357-360 | |
| Jérémy Lardon; Christophe Gravier; Jacques Fayolle | |||
| In our ubiquitous and pervasive society, Web contents are accessible from a
wide range of devices: PCs, smartphones, PDAs, but also TV set through a
SetTopBox. The main issue with the arrival of these new browsing devices is the
gap between their capabilities and the ones of a PC that most Web pages have as
a design reference. Web content adaptation is a scientific field that aims at
filling this gap by transforming Web content in order to fit the device
capabilities. In this paper, a novel architecture, DTEC (for DOM Tree
Estimation and Computation), is proposed for the automatic adaptation of Web
pages. Keywords: genetic algorithm, transcoding, transformation composition, web page
adaptation | |||
| User interface extensible markup language | | BIBAK | Full-Text | 361-362 | |
| David Faure; Jean Vanderdonckt | |||
| This workshop is aimed at investigating open issues in research and
development for user interface engineering based on User Interface eXtensible
Markup Language (UsiXML), a XML-compliant User Interface Description Language
and at reviewing existing solutions that address these issues. Keywords: multi-context, multi-device environments, multilinguality,
multi-organization, multi-user interfaces, multimodal | |||
| Design and engineering of game-like virtual and multimodal environments | | BIBAK | Full-Text | 363-364 | |
| Chris Raymaekers; Karin Coninx; Juan Manuel González-Calleros | |||
| This workshop brings together a number of researchers that are involved in
the design, engineering, evaluation and applicability of game-like virtual and
multimodal environments. It is a forum to discuss experiences, best practices,
and design and engineering approaches with a particular focus on those aspects
that are related to the interactivity of the game. Keywords: games, software engineering, virtual environments | |||
| Engineering patterns for multi-touch interfaces | | BIBAK | Full-Text | 365-366 | |
| Kris Luyten; Davy Vanacken; Malte Weiss; Jan Borchers; Shahram Izadi; Daniel Wigdor | |||
| Multi-touch gained a lot of interest in the last couple of years and the
increased availability of multi-touch enabled hardware boosted its development.
However, the current diversity of hardware, toolkits, and tools for creating
multi-touch interfaces has its downsides: there is only little reusable
material and no generally accepted body of knowledge when it comes to the
development of multi-touch interfaces. This workshop seeks a consensus on
methods, approaches, toolkits, and tools that aid in the engineering of
multi-touch interfaces and transcend the differences in available platforms.
The patterns mentioned in the title indicate that we are aiming to create a
reusable body of knowledge. Keywords: eics workshop, engineering patterns, multi-touch interfaces | |||
| Pattern-driven engineering of interactive computing systems (PEICS) | | BIBAK | Full-Text | 367-368 | |
| Kai Breiner; Marc Seissler; Gerrit Meixner; Peter Forbrig; Ahmed Seffah; Kerstin Klöckner | |||
| Since almost over one decade, patterns have been gaining a lot of interest
in the domain of Human-Computer-Interaction (HCI) engineering. It is generally
agreed upon that patterns can be used to facilitate the exchange of best
practices and knowledge between the interdisciplinary team members, involved in
interactive systems design process. Despite intense research activities in the
last years, HCI patterns still lack in a standardized description and
organization. This makes it difficult for the developers to identify the
relevant patterns for solving a problem as well as to apply them accordingly to
the problem context.
To fully benefit from HCI patterns within the engineering of interactive computer systems they have to be prepared for integration into a model-based user interface development process. Instead of guiding and advising the UI developers of which solution should be applied, HCI patterns should enable the easy reuse of already designed model or code fragments. To enable the integration of HCI patterns in the model-based development process the informal textual, or graphical notation of HCI patterns has to be overcome. HCI patterns have to support the formal description of their solution-part, which allows the direct integration of the solution-parts into the different models, like task-, dialog- and presentation-model. Keywords: hci pattern, model-based development | |||
| Bringing users' conceptual models into design: an introduction to CASSM analysis | | BIBAK | Full-Text | 369-370 | |
| Ann E. Blandford | |||
| Interactive systems have to fit the needs of their users. In an evolutionary
development cycle, the evaluation of existing systems serves as a foundation
for designing improved systems that better fit people's needs. Few evaluation
methods encourage the analyst to step back and consider how well a system
supports users' conceptual understandings and system utility. CASSM, the
approach presented in this course, focuses on the quality of 'fit' between
users and an interactive system. This course presents the methodology of
gathering suitable data and conducting a CASSM analysis, and show how CASSM can
help identify re-design possibilities to improve system utility. CASSM
complements established evaluation methods by focusing on conceptual structures
rather than procedures. It also provides a guiding framework for analysts
working with qualitative data such as think-aloud or interview protocols. Keywords: CASSM, conceptual fit, system evaluation | |||
| Model a discourse and transform it to your user interface | | BIBAK | Full-Text | 371-372 | |
| Hermann Kaindl | |||
| Every interactive system needs a user interface, today possibly even several
ones adapted for different devices (PCs, PDAs, mobile phones). Developing a
user interface is difficult and takes a lot of effort, since it normally
requires design and implementation. This is also expensive, and even more so
for several user interfaces for different devices.
This tutorial shows how human-computer interaction can be based on discourse modeling, even without employing speech or natural language. Our discourse models are derived from results of Human Communication theories, Cognitive Science and Sociology. Such discourse models can specify an interaction design. This tutorial also demonstrates how such an interaction design can be used for model-driven generation of user interfaces and linking them to the application logic and the domain of discourse. Keywords: discourse modeling, model-driven user interface generation | |||
| Mastering use cases: capturing functional requirements for interactive applications | | BIBAK | Full-Text | 373-374 | |
| Daniel Sinnig; Homa Javahery | |||
| Use cases were introduced in the early 90s by Jacobson. He defined a use
case as a "specific way of using the system by using some part of the
functionality." Use case modeling is making its way into mainstream practice as
a key activity in the software development process (e.g., Unified Process).
There is accumulating evidence of significant benefits to customers and
developers. The use case model is the artifact of choice for capturing
functional requirements and as such, serves as a contract of the envisioned
system behavior between stakeholders. It drives the architecture of the
application, it can be used to generate functional test cases and often serves
as a reference point for maintenance and documentation purposes. Writing
effective and well-structured use cases is a difficult task which requires a
deep understanding of the surrounding techniques and best practices. Current
practice has shown that it is easy to misuse them or make mistakes that can
unintentionally turn them into "abuse cases". Keywords: formalization, guidelines, heuristics, refactoring, use cases, user
interface models | |||