User-driven visual composition of service-based interactive spaces

doi:10.1016/j.jvlc.2014.01.003

Journal of Visual Languages & Computing

Volume 25, Issue 4, August 2014, Pages 278-296

https://doi.org/10.1016/j.jvlc.2014.01.003 Get rights and content

Abstract

Objective

The overall objective of the research work presented in this paper is to investigate models, methods and architectures to replace fixed, pre-packaged applications with flexible composition environments that make interactive environments “emerge” at run-time, based on composition actions performed by non-technical users. The approach aims at the lightweight construction of integrated, situational workspaces pervasively accessible and sharable through a variety of devices.

Methods

Based on a meta-design approach, we designed and implemented a platform that allows end users, not necessarily experts of technologies, to extract contents from heterogeneous sources and compose Personal Information Spaces (PISs) that satisfy their information needs. Specific emphasis is posed on the adoption of a composition paradigm that abstracts from technical details and can thus be used by non-technical users.

Results

The platform for service composition that supports the activity of the different involved stakeholders is described in details. Thanks to the separation of concerns on which the composition paradigm is based, the overall approach and its enabling platform are also amenable to customization with respect to the requirements of specific domains.

Conclusion

We present an approach where a composition platform enables the extraction of content from heterogeneous services and its integration into situational applications where content presentation is flexibly managed through different visual templates. We also discuss the advantages offered by this approach to the stakeholders of a specific community of users in the Cultural Heritage domain.

Practice

The developed prototypes were evaluated in laboratories and field studies: the former aimed at investigating the ease of use and the users satisfaction of the functionality and the user interface of the environment for domain customization, the latter aimed instead at observing real users (e.g., guides of an archeological park) in action, to assess the validity of the proposed composition paradigm as an EUD practice.

Implications

The user studies described in this paper provided hints for refining the prototypes, and laid the basis for future work related to the identification of design principles that can make service-based composition technologies in general more useful and usable for end users.

Introduction

Different work contexts and every-day life situations are nowadays characterized by activities where single users or groups of people, through different devices, browse heterogeneous content, capture, synthesize and annotate it to highlight insights and compose it in various ways, in order to create new content and applications. The huge amount of resources available on the Web provide a valuable source of content; but to enable an increasing number of people to make sense of such resources it is necessary to open up the construction of service-based software to non-programmers. Technologies for Web service composition have been proposed since the 1990s in the context of the Service Oriented Architecture (SOA) [1]. More recently, we have seen the proposal of platforms, based on mashup technologies, which claim to be more oriented towards end users [2]. However, this claim has proved to be unrealistic because of the inadequacy, for non-technical people, of the composition languages on which such platforms are based [3], [4], [5].

The overall goal of the research presented in this article is to investigate models, methods and architectures for supporting people, who are not software developers and have diverse needs, to co-create Personal Information Spaces (PISs), by integrating heterogeneous contents and artifacts. By PIS we mean an interactive space personalized by its creator that can facilitate access to and manipulation of contents and functionality, since it provides integrated views over disparate, distributed resources. Our goal is in line with the interest, growing both in academia and in industry, in elastic systems, able to support paradigms in which applications can be flexibly shaped up at different layers (data, functions and presentation) at use time, based on users’ actions in specific usage contexts. One important ingredient to achieve such a flexibility is separation of concerns: “contents, applications, and devices need to be decoupled as much as possible to allow users to focus on information without being confined to a particular pre-packaged application context” [6].

This article discusses the above issues and shows how we addressed them by developing a platform where a visual paradigm enables the lightweight construction of multi-device applications, through which users can easily access, integrate and manipulate information to satisfy their situational needs. We illustrate composition environments where users, by means of “content-exploratory” actions, seamlessly create applications, without the need for distinguishing among what design and execution are (which is typical of professional software design and programming), and are not forced to master technicalities to invoke and integrate data and services (which is typical of service management).

Empowering people, who may not have technical skills, with the possibility of composing content and services is a very critical challenge. The approach presented in this paper builds on recent experience in investigating paradigms for mashup composition [7], [8] and on the lessons learnt on End-User Development (EUD) [9], [10], [11], and tries to combine the advantages of both fields. This work is the result of an iterative set of experiences, which led us to identify some key points. One is about specializing a platform for mashup composition to a specific domain, thus capitalizing on the knowledge of people working in the domain, in order to offer a composition process that makes sense for a community of users [4]. In [12], we discussed the need for composition approaches to foster EUD and we reported some preliminary studies conducted to assess the adequacy of a composition platform in a specific domain, namely Cultural Heritage by better understanding how the envisioned platform could bring practical value to different stakeholders in the context of visits to sites of cultural interest. Based on these studies, we identified in particular the need for domain-specific resources, providing sensible, non-generic content, and for user interface (UI) templates, able to guide the composition, thanks to some basic visual elements that can be easily manipulated by non-technical people to create and modify their PIS. Thus, the significant, new contribution of this paper is a comprehensive methodology for service and data composition by end users, based on a meta-design approach and a novel “stratification” of the composition platform into layers, so that:

•
In accordance with meta-design, the overall approach enables the involvement of different stakeholders: the first phase (the meta-design phase) consists of designing software environments that allow some stakeholders to create templates, basic elements, and software environments appropriate for end users in the specific application domain; in the second phase, using such environments, end users are able to compose and manipulate their PIS.
•
In accordance with the need for domain-specific approaches, it enhances customization processes, easing the adoption of the approach by specific communities of end users.
•
In accordance with the need for elastic systems, it offers an “un-packaged” environment, where end users have the freedom to select the most adequate source of contents, visual templates and execution devices, and the logic to integrate contents deriving from different sources.

The article is organized as follows. Section 2 illustrates the motivations of the overall research work and Section 3 reports related work on service composition. Section 4 illustrates the meta-design approach to PIS composition. Section 5 describes the platform developed, addressing its main components and showing, with examples taken from the case study referring to visits to sites of cultural interest, the adopted visual interaction paradigms and how the platform is customizable to specific application domains. 6 Evaluation of the visual composition paradigm, 7 Evaluation of PIS creation and use in the CH domain report some formative studies we have performed to evaluate the platform components devoted to non-technical users. In particular, the study described in Section 7 involved professional guides and visitors of an archeological park. Section 8 finally outlines our conclusions.

Section snippets

Motivation

The emerging need for making software systems flexible, so as to increase their ability to support a large variety of tasks, is highlighted in recent works published in the literature. The idea is to replace fixed applications with elastic systems, where contents, functionality and access devices are totally decoupled from specific contexts of use and can be determined at runtime; elasticity is, in other words, introduced to accommodate multiple and variable contextual needs. New design

Composition of service-based interactive spaces

Our work addresses the construction by the end users of Personal Information Spaces (PISs). This term was used in [26] to define an informal space that consists of both artifacts and assigned meanings, constructed, interpreted and manipulated by only one person. In the context of our research, we define PISs as personalized service-based interactive environments, where people, who are not software developers, integrate, manipulate and share heterogeneous contents and artifacts coming from

Meta-design approach to PIS creation

Our approach for the lightweight composition of PISs is contextualized within a meta-design approach, based on the Software Shaping Workshop (SSW) model that some of the authors have developed [19], [44]. This design model underlines the creation of software infrastructures that support EUD activities and knowledge co-creation by the different stakeholders involved in system design. All stakeholders of an interactive system, including end users, are “owners” of a part of the problem: software

The platform for PIS composition and use

To support the meta-design scenario illustrated above, we have developed a platform prototype which extends a general-purpose mashup environment [7] to respond to the need for introducing customized elements (e.g., components, visual templates and composition mechanisms) that are adequate for specific communities of users. The general composition platform is characterized by a “lightweight” composition paradigm, in which direct manipulation of visual elements enables the creation of new

Evaluation of the visual composition paradigm

The composition platform has been designed according to a user-centered approach, which prescribes iterative development and prototype evaluation [60]. We performed formative evaluations by triangulating different methods, including studies for collecting feedback in a real context of use. Two usability tests were carried out to evaluate the visual paradigm adopted in the SCE to select and package new resources. Specifically, Section 6.1 illustrates the results of a usability study involving 10

Evaluation of PIS creation and use in the CH domain

In the early phases of design and development of the case study, which addresses the creation of PISs to enrich the visit experience at Cultural Heritage sites, a participatory design team was set up. It also included professional guides with a long experience in conducting visits to archeological parks and museums, who regularly create multimedia presentations for the lectures that they give in schools and cultural clubs. The guides were observed while leading several groups of visitors and

Conclusion and future work

This paper has illustrated how, capitalizing on the synergy between service composition technologies and EUD approaches based on a meta-design paradigm, we have designed and implemented a platform that allows end users, who are not necessarily experts of technologies, to compose Personal Information Spaces (PISs) that satisfy their situational needs and that can be pervasively executed on different devices. Starting from a general-purpose platform for mashup composition, we have identified how

Acknowledgments

This work was partially supported by the Italian Ministry of University and Research (MIUR) under the VINCENTE grant and by the Italian Ministry of Economic Development under the LOGIN grant. We are extremely grateful to the director and the personnel of the Egnathia Archeological Park, and to the professional guides Achille Chillà and Conny Blasi who took part in our field study. We also thank organizers and participants of the EUD4Services 2012 workshop for the interesting discussions from

References (65)

C. Ardito et al.
End users as co-designers of their own tools and products
J. Vis. Lang. Comput.
(2012)
S. Trewin et al.
Abstract representations as a basis for usable user interfaces
Interact. Comput.
(2004)
K. Hornbæk
Current practice in measuring usability: challenges to usability studies and research
Int. J. Hum. Comput. Stud.
(2006)
G. Alonso et al.
Web Services: Concepts, Architectures and Applications
(2004)
F. Daniel et al.
Next in Mashup Development: User-Created Apps on the Web
IT Professional
(2011)
N. Zang, M.B. Rosson, What׳s in a mashup? And why? Studying the perceptions of web-active end users, in: Proceedings of...
A. Namoun et al.
Conceptual and usability issues in the composable web of software services
F. Casati
How end-user development will save composition technologies from their continuing failures
M. Latzina et al.
Transformative user experience: beyond packaged design
Interactions
(2012)
C. Cappiello et al.
Enabling end user development through mashups: requirements, abstractions and innovation toolkits

C. Cappiello et al.

DashMash: a mashup environment for end user development

A. Sutcliffe et al.

End-user development (introduction to special issue)

Commun. ACM

(2004)

C. Ardito, M.F. Costabile, G. Desolda, M. Matera, A. Piccinno, M. Picozzi, Composition of situational interactive...

H. Werner, M. Latzina, M. Brade, Symbik – a new medium for collaborative knowledge-intensive work, in: Proceedings of...

Y. Jin et al.

Understanding mashup development

IEEE Internet Comput.

(2008)

F. Daniel et al.

Hosted universal composition: models, languages and infrastructure in mashArt

M. Spahn et al.

End-user development for individualized information management: analysis of problem domains and solution approaches

A. Dix, Designing for appropriation, in: Proceedings of the 21st British HCI Group Annual Conference on People and...

G. Fischer et al.

Meta-design: a manifesto for end-user development

Commun. ACM

(2004)

M.F. Costabile et al.

Visual interactive systems for end-user development: a model-based design methodology

IEEE Trans. Syst. Man Cybern. A

(2007)

M.F. Costabile et al.

Supporting end users to be co-designers of their tools

G. Fischer

Understanding, fostering, and supporting cultures of participation

Interactions

(2011)

H. Jenkins

Confronting the Challenges of Participatory Culture: Media Education for the 21st Century

(2009)

D. Díez et al.

Cultures of participation in the digital age: empowering end users to improve their quality of life

J. Porter

Designing for the Social Web

(2008)

C. Tang, S. Carpendale, An observational study on information flow during nurses׳ shift change, in: Proceedings of the...

L. Bannon, S. Bødker, Constructing common information spaces, in: Proceedings of the 5th Conference on European...

A. Boden et al.

Tangible and screen-based interfaces for End-user Workflow Modeling

Software, IEEE, PP

(2013)

M. Cáceres, Packaged web apps (widgets) – packaging and XML configuration, 2nd ed., W3C Recommendation, 2012...

E.M. Maximilien et al.

Language for web APIs and services mashups

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View full text

User-driven visual composition of service-based interactive spaces

Abstract

Objective

Methods

Results

Conclusion

Practice

Implications

Introduction

Section snippets

Motivation

Composition of service-based interactive spaces

Meta-design approach to PIS creation

The platform for PIS composition and use

Evaluation of the visual composition paradigm

Evaluation of PIS creation and use in the CH domain

Conclusion and future work

Acknowledgments

J. Vis. Lang. Comput.

Interact. Comput.

Int. J. Hum. Comput. Stud.

Web Services: Concepts, Architectures and Applications

Next in Mashup Development: User-Created Apps on the Web

IT Professional

Conceptual and usability issues in the composable web of software services

How end-user development will save composition technologies from their continuing failures

Transformative user experience: beyond packaged design

Interactions

Enabling end user development through mashups: requirements, abstractions and innovation toolkits

DashMash: a mashup environment for end user development

End-user development (introduction to special issue)

Commun. ACM

Understanding mashup development

IEEE Internet Comput.

Hosted universal composition: models, languages and infrastructure in mashArt

End-user development for individualized information management: analysis of problem domains and solution approaches

Meta-design: a manifesto for end-user development

Commun. ACM

Visual interactive systems for end-user development: a model-based design methodology

IEEE Trans. Syst. Man Cybern. A

Supporting end users to be co-designers of their tools

Understanding, fostering, and supporting cultures of participation

Interactions

Confronting the Challenges of Participatory Culture: Media Education for the 21st Century

Cultures of participation in the digital age: empowering end users to improve their quality of life

Designing for the Social Web

Tangible and screen-based interfaces for End-user Workflow Modeling

Software, IEEE, PP

Language for web APIs and services mashups