Saeed Aghaee

End-User Development of Mashups with NaturalMash

Context: The emergence of the long-tail in the market of software applications is shifting the role of end-users from mere consumers to becoming developers of applications addressing their unique, personal, and transient needs. On the Web, a popular form of such applications is called mashup, built out of the lightweight composition of Web APIs (reusable software components delivered as a service through the Web). To enable end-users to build mashups, there is a key problem that must be overcome: End-users lack programming knowledge as well as the interest to learn how to master the complex set of Web technologies required to develop mashups. End-User Development (EUD) is an emerging research field dealing with this type of problems. Its main goal is to design tools and techniques facilitating the development of software applications by non-programmers. Objective: The paper describes the design and evaluation of NaturalMash, an innovative EUD tool for mashups (a mashup tool). NaturalMash aims at enabling non-professional users without any knowledge of programming languages and skills to create feature-rich, interactive, and useful mashups. Methods: The design of NaturalMash adopts a formative evaluation approach, and has completed three design and evaluation iterations. The formative evaluations utilize usability testing, think aloud protocol, questionnaires, observation, and unstructured interviews. Additionally, we compare the expressive power of naturalmash with the state-of-the-art mashup tools. Results: The results from the formative evaluations helped us identify important usability problems. From an assessment point of view, the results were promising and sggested that the proposed tool has a short and gentle learning curve in a way that even non-programmers are able to rapidly build useful mashups. Also, the comparative evaluation results showed that NaturalMash offers a competitive level of expressive power compared with existing mashup tools targeting non-programmers. Conclusion: As the evaluation results indicate, NaturalMash provides a high level of expressive power while it is still highly usable by non-programmers. These suggest that we have successfully achieved the objective of the proposed tool, distinguishing it from existing mashup tools that are either too limited or highly specialized for non-professional users.

Reusable decision space for mashup tool design

Mashup tools are a class of integrated development environments that enable rapid, on-the-fly development of mashups - a type of lightweight Web applications mixing content and services provided through the Web. In the past few years there have been growing number of projects, both from academia and industry, aimed at the development of innovative mashup tools. From the software architecture perspective, the massive effort behind the development of these tools creates a large pool of reusable architectural decisions from which the design of future mashup tools can derive considerable benefits. In this paper, focusing on the design of mashup tools, we explore a design space of decisions comprised of design issues and alternatives. The design space knowledge not only is broad enough to explain the variability of existing tools, but also provides a road-map towards the design of next generation mashup tools.

Mashup development with HTML5

HTML5 is a new technology standard promising to empower browsers to become a suitable platform for developing rich Web applications. Whilst it is still considered an emerging technology, in this paper we attempt to capture and explore its impacts on mashup development. To do so, we start with a mashup case study showcasing new HTML5 features. We then move on to explore those aspects of mashup development that are affected and will possibly be enabled by HTML5 in the near future. These aspects are grouped into two categories: short-term impacts, that can be harnessed by mashup developers, and long-term impacts, that should be considered by service/content providers.

End-User programming for web mashups: Open research challenges

Mashup is defined as the practice of lightweight composition, serendipitous reuse, and user-centric development on the Web. In spite of the fact that the development of mashups is rather simple due to the reuse of all the required layers of a Web application (functionality, data, and user interface), it still requires programming experience. This is a significant hurdle for non-programmers (end-users with minimal or no programming experience), who constitute the majority of Web users. To cope with this, an End-User Programming (EUP) tool can be designed to reduce the barriers of mashup development, in a way that even non-programmers will be able to create innovative, feature-rich mashups. In this paper, we give an overview of the existing EUP approaches for mashup development, as well as a list of open research challenges.

EnglishMash: usability design for a natural mashup composition environment

The design of mashup tools combines elements from end-user development and software composition in the context of the Web. The challenge for mashup tool designers is to provide end-users with suitable abstractions, programming models and tool support for easily composing mashups out of existing Web services and Web data sources. In this paper we describe the design of a natural mashup composition environment based on the EnglishMash controlled natural language. The environment proactively supports users as they are learning the syntax of the EnglishMash language with features such as auto-completion, immediate feedback, live preview of the mashup execution and component discovery and selection based on natural language descriptions.

An evaluation of mashup tools based on support for heterogeneous mashup components

Mashups are built by combining building blocks, which are commonly referred to as mashup components. These components are characterized by a high level of heterogeneity in terms of technologies, access methods, and the behavior they may exhibit within a mashup. Abstracting away this heterogeneity is the mission of the so-called mashup tools aiming at automating or semi-automating mashup development to serve non-programmers. The challenge is to ensure this abstraction mechanism does not limit the support for heterogeneous mashup components. In this paper, we propose a novel evaluation framework that can be applied to assess the degree to which a given mashup tool addresses this challenge. The evaluation framework can serve as a benchmark for future improved design of mashup tools with respect to heterogeneous mashup components support. In order to demonstrate the applicability of the framework, we also apply it to evaluate some existing tools.

The mashup component description language

Mashups can be seen as the result of software composition applied to the Web. One of the characteristics of mashup development is the heterogeneity of its building components in terms of logical layering (e.g., user interface, application logic, and data), access method (e.g., REST, SOAP), and composition technique (e.g., scraping vs. clipping, synchronous vs. asynchronous interaction, discrete vs. streaming). This poses a challenge towards the design of mashup tools aiming at lowering the barriers of mashup development, as this heterogeneity needs to be abstracted. In this paper, we address this challenge by proposing a new JSON-based domain-specific language for describing heterogeneous mashup components, called the Mashup Component Description Language (MCDL). MCDL lies at the core of a meta-model for mashup component modeling, and can be used for component discovery and classification but also for user-centric mashup development as it decouples the interface of a mashup component from its underlying implementation technologies.

Natural End-User Development of Web Mashups

End-User Development (EUD) can be exploited on the Web, where users have the opportunity to create niche “Web Mashup” applications as a means to address their long tail of situational needs in different domains of application. In this paper, we describe the design and evaluation of NaturalMash, an innovative EUD system for mashups. NaturalMash provides a high level of expressive power while it is still usable by non-professional users. This clearly distinguishes NaturalMash from existing mashup EUD tools that are either too limited or highly specialized for inexperienced users. The NaturalMash user interface efficiently combines different techniques such as live programming, natural language programming, What You See Is What You Get (WYSIWYG), and Programming by Demonstration (PbD). The design of NaturalMash adopts a formative evaluation approach, and has completed two design and evaluation iterations. The paper reports the results of the last formative evaluation and discusses the implications of the findings. The results are promising and suggest that the proposed system has a short and gentle learning curve and enables even non-professional users to rapidly build useful mashups.

Live mashup tools: challenges and opportunities

Live programming is a programming style in which the repetitive task of compiling and running the software being programmed is managed automatically. This style can be a helpful practice in End-User Development (EUD) where the nonprofessional end-users are to be supported through techniques and tools that empower them to create or modify software artifacts. Mashups a form of lightweight Web applications composing reusable content and functionalities available on the Web are a popular target for EUD activities on the Web. EUD for mashups is enabled by intuitive composition environments, called mashup tools. In this paper, we introduce live mashup tools, a new class of mashup tools based on the live programming style. We give a comprehensive definition and classification of live mashup tools, giving examples of how well existing tools fit in this category and discuss open research challenges and opportunities.

Guidelines for Efficient and Effective End-User Development of Mashups

End-User Development (EUD) is an emerging research area aiming at empowering non-technical users to somehow create or design software artifacts. Mashups provide a high potential for EUD activities on the Web. Users on the Web can tap into a vast resource of off-the-shelf components in order to rapidly compose new lightweight software applications called mashups. In this paper, we provide a set of guidelines to design EUD systems for mashups that are widely referred to as mashup tools. The guidelines are derived from our experience with the (ongoing) design and evaluation of NaturalMash, a novel mashup tool targeted for a wide range of users to create feature-rich mashups.