Christian Gütl

On using JSON-LD to create evolvable RESTful services

As the amount of data and devices on the Web experiences exponential growth issues on how to integrate such hugely heterogeneous components into a scalable system become increasingly important. REST has proven to be a viable solution for such large-scale information systems. It provides a set of architectural constraints that, when applied as a whole, result in benefits in terms of loose coupling, maintainability, evolvability, and scalability. Unfortunately, some of RESTs constraints such as the ones that demand self-descriptive messages or require the use of hypermedia as the engine of application state are rarely implemented correctly. This results in tightly coupled and thus brittle systems. To solve these and other issues, we present JSON-LD, a community effort to standardize a media type targeted to machine-to-machine communication with inherent hypermedia support and rich semantics. Since JSON-LD is 100% compatible with traditional JSON, developers can continue to use their existing tools and libraries. As we show in the paper, JSON-LD can be used to build truly RESTful services that, at the same time, integrate the exposed data into the Semantic Web. The required additional design costs are significantly outweighed by the achievable benefits in terms of loose coupling, evolvability, scalability, self-descriptiveness, and maintainability.

Collaborative virtual 3D environment for internet-accessible physics experiments

Abstractâ??Immersive 3D worlds have increasingly raised the interest of researchers and practitioners for various learning and training settings over the last decade. These virtual worlds can provide multiple communication channels between users and improve presence and awareness in the learning process. Consequently virtual 3D environments facilitate collaborative learning and training scenarios. In this paper we focus on the integration of internet-accessible physics experiments (iLabs) combined with the TEALsim 3D simulation toolkit in Project Wonderland, Suns toolkit for creating collaborative 3D virtual worlds. Within such a collaborative environment these tools provide the opportunity for teachers and students to work together as avatars as they control actual equipment, visualize physical phenomenon generated by the experiment, and discuss the results. In particular we will outline the steps of integration, future goals, as well as the value of a collaboration space in Wonderlands virtual world.

Attrition in MOOC: Lessons Learned from Drop-Out Students

Despite the popularity of Massive Open Online Course (MOOC), recent studies have found that completion rates are low with some reported to be significantly lower than 10%. The low retention and completion rates are major concerns for educators and institutions. This paper investigates motivations for enrolling in a MOOC on the topic of ‘e-learning’ and discusses reasons for the attrition rates during the course. A survey of 134 students who had not completed the MOOC reveals that only 22% of the students had intended to complete the MOOC but was unable to due to various factors including academic and personal reasons. A big majority of the students indicated that changes in their job, insufficient time, difficulty with the subject matter and unchallenging activities are some of the reasons for the drop-out.

Motivational active learning: engaging university students in computer science education

Attracting and engaging computer science students to enhance their mathematical and algorithmic thinking skills are challenging tasks. In winter 2013 we introduced a new teaching format for a course, which combines theory in computer science with hands-on algorithmic challenges, mathematical thinking activities, and collaborative problem-solving. Therefore, we introduced the pedagogical model Motivational Active Learning (MAL), which is grounded in MITs successful format for teaching physics, Technology-Enabled Active Learning (TEAL), and combines it with motivational strategies usually used by game designers. Results from the initial setup in class reveals that students indeed assessed the course structure as more interactive and motivating compared to other similar courses. In this paper we discuss the course design, issues, and the impact, and analyze the first results in detail.

Evaluation of collaborative learning settings in 3D virtual worlds

Virtual 3D worlds are gaining popularity among the general population and the virtual world environment is widely used particularly by the younger generations as a knowledge and social tool. In recent years, universities have conducted experiments with the use of virtual 3D worlds for teaching and learning. Virtual 3D worlds are no longer just for the stereotypical geek. By 2011 it is estimated that about 80% of active Internet users will have an â??avatar

A semantic description language for RESTful Data Services to combat Semaphobia

RESTful Web services are an increasingly popular way for companies to expose their data on the Web. On the other hand, the Linked Open Data initiative is gaining traction recently. Since RESTs principles align well with those of Linked Data, there is an increasing interest in the relationship of the two. Nevertheless, in practice they still largely remain separated, creating islands of data instead of a global graph of data forming the envisioned Semantic Web. There are different reasons for this. One is the reluctance of most Web developers to use Semantic Web technologies, a phenomenon we denote as Semaphobia. Another reason is that the Semantic Web is considered to be a disruptive technology which does not consider existing infrastructure. This makes it difficult for enterprises to update their legacy systems. To solve these and other issues, we propose a novel approach to semantically describe RESTful Data Services which in consequence leads to a mechanism to transform the data provided by such services to semantic resources. This aims to contribute to the availability of more semantic datasets. By keeping the approach as familiar and simple as possible for Web developers, we hope to lower the entry barrier and to foster the adoption of our approach.

Search result visualisation with xFIND

The xFIND gatherer-broker architecture provides a wealth of metadata, which can be used to provide sophisticated search functionality. Local or remote documents are indexed and summaries and metadata are stored on an xFIND broker (server). An xFIND client can search a particular broker and access rich metadata for search result presentation, without having to fetch the original documents themselves. Search result sets are not only presented as a traditional ranked list, but also in an interactive scatterplot (Search Result Explorer) and using dynamic thematic clustering (VisIslands).

Towards a RESTful service ecosystem

Average information workers spend most of their time for searching, analyzing, reformatting and consolidating information. The recent advent of service-oriented architectures (SOA) built on Web services is a first attempt to streamline respectively automate those tasks in order to increase productivity. SOAP-based services work well within a company and are thus mainly used to for the integration of legacy systems which have not been built to be Web-friendly or to make new systems more flexible for changing requirements in business ecosystems. Nevertheless, the utopian promise of uniform service interface standards, metadata and universal service registries, in the form of the SOAP, WSDL and UDDI standards have proven elusive. Instead, for Internet-scale applications, lightweight REST-based architectures which gained a lot of momentum recently provide a number of important advantages such as better scalability, reliability and visibility and are thus the preferred choice for Internet-scale applications. Despite the foreseeable potential, the increasing interest on and growing acceptance of lightweight services, there are still problems on formal describing, finding and orchestrating services as well as a lack of a holistic framework covering the entire service lifecycle. This paper focuses on an extensive survey comparing the traditional SOAP-based architecture to the emergent lightweight REST-based architectural style as a first step towards a framework proposal.

MOOC in Latin America: Implementation and Lessons Learned

A critical review on MOOCs is provided in this paper. A discussion on the different types of MOOCs and the design of a MOOC learning experience in South America forms the basis of this paper. The MOOC presented utilized cloud-based tools for deployment of the learning activities. Findings on usability, emotional and motivation aspects from 143 participants who had completed the MOOC course are discussed in this paper. Restrictions to pre-selected cloud-based tools and communication channels as well as guidance provided to the participants revealed positive learners’ attitudes on usability, emotional and motivation aspects.

SOA-based architecture for a generic and flexible e-assessment system

In the last decade, universities and higher education institutes have become more and more interested in using computers to deliver their formative and summative assessments. Therefore, several computer-assisted-assessment systems have been developed. The variance in the application domains of e-assessment has a main influence on having different assessment systems in the same university. Since universities have different colleges and specializations based on their types and in order to deliver their assessment activities online, each college is developing or buying assessment system or tools based on its specializations and courses. This has caused some universities to have more than one computer-assisted-assessment system. In this paper, a service-oriented e-assessment system will be suggested to solve this problem. A service-oriented architecture for a generic and flexible assessment system will be provided with cross-domain use cases to show the flexibility of this architecture.