Sebastian Heil

MockAPI: an agile approach supporting API-first web application development

In the last years, agile development methodologies have been widely adopted. However, they still lack support for API requirements while, at the same time, public RESTful APIs are fueling a rapid growth of web applications providing services built on other services. On the other hand, whereas Model-Driven Development techniques successfully increase the productivity in the development of data-intensive web applications, they lack the agility required when developing heterogeneous web applications with frequent requirement changes. In this paper we introduce MockAPI, an approach based on annotating user interface mockups that combines the advantages of agile approaches and Model-Driven Development. We introduce a metamodel for annotations and demonstrate how to derive running API prototypes as starting point for agile development. RESTful API best practices and API-first development are introduced into the agile process. The MockAPI approach defines a set of constraints to accelerate the development of web applications. We also show the results of a brief validation applying MockAPI to popular web sites.

Collaborative adaptive case management with linked data

An increasing share of todays work is knowledge work. Adaptive Case Management (ACM) assists knowledge workers in handling this collaborative, emergent and unpredictable type of work. Finding suitable workers for specific functions still relies on manual assessment and assignment by persons in charge, which does not scale well. In this paper we discuss a tool for ACM to facilitate this expert finding leveraging existing Web technology. We propose a method to automatically recommend a set of eligible workers utilizing linked data, enriched user profile data from distributed social networks and information gathered from case descriptions. This semantic recommendation method detects similarities between case requirements and worker profiles. The algorithm traverses distributed social graphs to retrieve a ranked list of suitable contributors to a case according to adaptable metrics. For this purpose, we introduce a vocabulary to specify case requirements and a vocabulary to describe skill sets and personal attributes of workers. The semantic recommendation method is demonstrated by a prototypical implementation using a WebID-based distributed social network.

Customized views on profiles in WebID-Based distributed social networks

WebID as an extensible and distributed identification approach enables users to globally authenticate themselves, connect to each other and manage their identity data at a self-defined place. Identity data stored in WebID profile documents can be protected from unauthorized access using appropriate access control methods. While existing methods are primarily about securing resources, they lack providing adequate mechanisms for controlling access to specific data within profiles. This paper presents our approach to create customized views on profiles in WebID-based distributed social networks. We introduce fine-grained personalized filters based on SPARQL templates and demonstrate their integration into an existing identity management platform.

Protecting User Profile Data in WebID-Based Social Networks Through Fine-Grained Filtering

The WebID identification approach allows users to manage their profile data at a self-defined place in the cloud and enables services as well as other requesters to retrieve data stored within these profiles. While existing access control mechanisms can secure entire user profiles from unauthorized access, they lack fine-grained protection of sensitive data within user profiles. This paper presents an approach for applying requester-specific filters to cloud-stored user profile data in WebID-based distributed social networks. Our approach aims at enabling profile owners to protect sensitive user data within their profiles in a fine-grained manner. We demonstrate our solution by integrating the approach into a WebID identity provider and profile management platform.

Measuring and Ensuring Similarity of User Interfaces: The Impact of Web Layout

Given the rapid update cycles in modern web information systems and the abundance of legacy software being migrated to the web, controlling similarity between user interfaces (UI) is an actual problem of interaction engineering. The similarity (consistency) aspect is also increasingly considered in computer-aided design, where it is included in the optimized goal function, to minimize re-learning effort for users. In this paper, we explore the impact of the proposed layout distance measure, which is calculated for different levels of hierarchy in web UIs, which we identify as: Region – Block – Group – Element. To support our approach, we conducted an experimental pilot study in the context of an ongoing medical information system (IS) web migration project. The regression analysis suggests that layout distance (particularly, its orientation dimension) does have effect on web UI similarity as perceived by users. The results can be used by web engineers, in particular to smoothen the transition between versions of a UI for users and IS operators.

ProProtect3: An Approach for Protecting User Profile Data from Disclosure, Tampering, and Improper Use in the Context of WebID

WebID is a new identification approach of the W3C. It enables managing profile data associated to persons and services at self-defined places in the cloud. By relying on RDF vocabularies like FOAF for describing user profile data, WebID contributes to the Semantic Web vision. While access to user profiles can be controlled with existing security mechanisms, they are not designed to protect sensitive data within user profiles from unwanted retrieval, malicious manipulation, and improper use. This article analyzes the risks that affect the knowledge stored in WebID-based user profiles. It therefore describes potential attack scenarios and outlines the challenges a solution must deal with. To tackle the problem of insufficient protection, we propose ProProtect3. This approach enables identity owners (1) to create customized filters for sensitive data, (2) to verify the profile data integrity, and (3) to restrict the rights of delegatees. For evaluating the ProProtect3 approach, we integrate it into a WebID identity provider.

An Extensible, Model-Driven and End-User Centric Approach for API Building

The implementation of APIs in new applications is becoming a mandatory requirement due to the increasing use of cloud-based solutions, the necessity of integration with ubiquitous applications (like Facebook or Twitter) and the need to facilitate multi-platform support from scratch in the development. However, there is still no theoretically sound process for defining APIs (starting from end-user requirements) or their productive development and evolution, which represents a complex task. Moreover, high-level solutions intended to boost productivity of API development (usually based on Model-Driven Development methodologies) are often difficult to adapt to specific use cases and requirements. In this paper we propose a methodology that allows capturing requirements related to APIs using end-user-friendly artifacts. These artifacts allow quickly generating a first running version of the API with a specific architecture, which facilitates introducing refinements in it through direct coding, as is commonly accomplished in code-based Agile processes.

Web Intelligence Linked Open Data for Website Design Reuse

Code and design reuse are as old as software engineering industry itself, but it’s also always a new trend, as more and more software products and websites are being created. Domain-specific design reuse on the web has especially high potential, saving work effort for thousands of developers and encouraging better interaction quality for millions of Internet users. In our paper we perform pilot feature engineering for finding similar solutions (website designs) within Domain, Task, and User UI models supplemented by Quality aspects. To obtain the feature values, we propose extraction of website-relevant data from online global services (DMOZ, Alexa, SimilarWeb, etc.) considered as linked open data sources, using specially developed web intelligence data miner. The preliminary investigation with 21 websites and 82 human annotators showed reasonable accuracy of the data sources and suggests potential feasibility of the approach.

Web Migration - A Survey Considering the SME Perspective.

Legacy systems are business-critical and contain valuable knowledge gathered over years of development. Many of these systems are still non-web desktop applications. Companies are aware of the advantages of web applications. However, Web Migration (WM), i.e. transforming legacy systems into web applications, is still a challenge, in particular for Small and Medium-sized Enterprises (SMEs). A large body of research exists in this field, but the specifics of SMEs have been overseen so far. This survey provides an overview on existing WM approaches with a dedicated focus on the SME perspective. The systematic mapping study analyses 122 primary studies and tools, identifies four major research focuses, reports on common methods and techniques and the consideration of SMEs. We then outline resulting research issues and future research directions.

Extending Kansei Engineering for Requirements Consideration in Web Interaction Design

In our paper we consider how the eminent Kansei Engineering (KE) method can be applied in computer-aided development of websites. Although principally used for exploring emotional dimension of users’ experience with products, KE can be extended to incorporate other types of software requirements. In conjunction with AI Neural Networks (Kansei Type II), it then becomes possible to automate, up to a certain degree, evaluation of website quality in terms of functionality, usability, and appeal. We provide an overview of existing works related to KE application in web design, and note its certain gap with systematic Web Engineering. Then we summarize approaches for auto-validation of different types of requirements, with particular focus on computer-aided usability evaluation. Finally, we describe the ongoing experimental study we undertook with 82 participants, in which a Kansei-based survey with 21 university websites was performed, and outline preliminary results and prospects.