Nikos Karousos

Tackling Cognitively-Complex Collaboration with CoPe_it!

CoPe_it! is an innovative Web-based tool that complies with collaborative practices to provide members of communities with the appropriate means to manage individual and collective knowledge during a sense-making and/or decision-making session. In this article, we demonstrate its applicability in tackling cognitively-complex collaboration settings, which are characterized by big volumes of interrelated data obtained from diverse sources and knowledge expressed by diverse participants. We focus on issues related to the representation of such settings and propose an approach to make it easier for participants to follow the evolution of collaboration, comprehend it in its entirety, and meaningfully aggregate data to resolve the issue under consideration.

Naming as a fundamental concept of open hypermedia systems

Names play a key role in distributed hypertext systems, for two main reasons: Firstly, because accessing and managing system services require finding and locating the relevant components. Secondly, because managing structures between hypertext resources, such as nodes, anchors and links, requires that these resources are named and addressed. We argue that naming services are endemic to hypertext systems and therefore, form a core part of any hypertext system’s infrastructure. In particular, the current move towards interoperable component-based Open Hypermedia Systems (CB-OHS) demonstrates the need for naming components.

Offering open hypermedia services to the WWW: a step-by-step approach for developers

Hypermedia systems and more specifically open hypermedia systems (OHS) provide a rich set of implementations of different hypertext flavors such as navigational hypertext, spatial hypertext or taxonomic hypertext. Additionally, these systems offer component-based modular architectures and address interoperability between hypertext domains. Despite multiple efforts of integrating Web clients, a widespread adoption of OHS technology by Web developers has not taken place. In this paper it is argued that Web Services - which offer a component model for Web applications - can be integrated in OHSs. An architectural integration is proposed, a step-by-step process is outlined and an example of integration is provided. This very approach is aimed to benefit both worlds: the Web community with new rich hypermedia functionality that extends the current navigational hypermedia, and the OHS community by opening its tools and platforms to the many developer groups of the Web community.

Recognizing Emotions in Human Computer Interaction: Studying Stress Using Skin Conductance

This paper reports an experiment for stress recognition in human-computer interaction. Thirty-one healthy participants performed five stressful HCI tasks and their skin conductance signals were monitored. The selected tasks were most frequently listed as stressful by 15 typical computer users who were involved in pre-experiment interviews asking them to identify stressful cases of computer interaction. The collected skin conductance signals were analyzed using seven popular machine learning classifiers. The best stress recognition accuracy was achieved by the cubic support vector machine classifier both per task (on average 90.8 %) and for all tasks (Mean = 98.8 %, SD = 0.6 %). This very high accuracy demonstrates the potentials of using physiological signals for stress recognition in the context of typical HCI tasks. In addition, the results allow us to move on a first integration of the specific stress recognition mechanism in PhysiOBS, a previously-proposed software tool that supports researchers and practitioners in user emotional experience evaluation.

Evaluating User's Emotional Experience in HCI: the PhysiOBS Approach

As computing is changing parameters, apart from effectiveness and efficiency in human-computer interaction, such as emotion have become more relevant than before. In this paper, a new tool-based evaluation approach of user’s emotional experience during human-computer interaction is presented. The proposed approach combines user’s physiological signals, observation data and self-reported data in an innovative tool (PhysiOBS) that allows continuous and multiple emotional states analysis. To the best of our knowledge, such an approach that effectively combines all these user-generated data in the context of user’s emotional experience evaluation does not exist. Results from a preliminary evaluation study of the tool were rather encouraging revealing that the proposed approach can provide valuable insights to user experience practitioners.

Learning Management Systems and Learning 2.0

The unprecedented growth of Web 2.0 has affected learning and has made the growth of learning networks possible. Learning networks are shaped by communities to help their members acquire knowledge in specific areas and are the most notable feature of Learning 2.0, the new learning era that focuses on individual learning needs. The evolution of learning forces traditional Learning Management Systems LMS to incorporate more Web 2.0 features and slowly transform to Personal Learning Environments PLEs. A Personal Learning Environment is a loosely structured collection of tools with strong social networking characteristics, which gives users the ability to create, maintain, and redistribute their own learning content. This paper is a field study of the most well-known and established LMSs and their support for specific features within several categories of tools of Web 2.0. The incorporation of Web 2.0 features within those LMSs differentiates them regarding their ability and potential to be used as PLEs.

Usability Evaluation of Web-Based Collaboration Support Systems: The Case of CoPe_it!

Usability is considered as a very significant factor towards the wide acceptance of software applications. Although the usability evaluation can take place in different forms, the entire evaluation procedure usually follows predefined ways according to a classification of the common characteristics of software applications. However, contemporary Web 2.0 applications, which aim at both social network development and collaboration support, reveal the need for modifying the settings of the evaluation procedure. This is due to some unique characteristics of these applications, such as the support of both synchronous and asynchronous collaboration, the use of common spaces for working and information exchanging, and the advanced notification and awareness services. This paper explores these applications’ particularities with respect to the way the whole usability evaluation procedure is affected and proposes a composite evaluation technique based on the development of appropriate heuristics that is suitable for such cases. The aforementioned issues are elaborated through the case of CoPe_it!, a Web 2.0 tool that facilitates and enhances argumentative collaboration.

Developer Support in Open Hypermedia Systems: Towards a Hypermedia Service Discovery Mechanism

This paper argues that the open hypermedia research community should focus on the developer support issue. An enabling step to this target is the provision of an effective and easy-to-use hypermedia service discovery mechanism. The inexistence of such kind of mechanism, for finding and using hypermedia services, amongst the Open Hypermedia Systems (OHSs) is one of the main reasons for their narrow publicity and usage. Aiming to the improvement of the third party (hypermedia-unaware) developer support, the hypermedia service discovery mechanism will boost the OHS usage by providing a standard platform and a set of tools in order to enable the enhancement of third party applications with hypermedia functionality.

KLM Form Analyzer: Automated Evaluation of Web Form Filling Tasks Using Human Performance Models

Filling forms is a common and frequent task in web interaction. Therefore, designing web forms that enhance users’ efficiency is an important task. This paper presents a tool entitled KLM Form Analyzer (KLM-FA) that enables effortless predictions of execution times of web form filling tasks. To this end, the tool employs established models of human performance, namely the Keystroke Level Model and optionally the Fitts’ law. KLM-FA can support various evaluation scenarios, both in a formative and summative context, and according to different interaction strategies or modeled users’ characteristics. A study investigated the accuracy of KLM-FA predictions by comparing them to participants’ execution times for six form filling tasks in popular social networking websites. The tool produced highly accurate predictions (89.1% agreement with user data) in an efficient manner.

Stress in interactive applications: analysis of the valence-arousal space based on physiological signals and self-reported data

Measuring users’ emotional reaction to interactive multimedia and hypermedia is important. One particularly popular self-reported method for emotion assessment is the Valence-Arousal (VA) Scale: a 9 × 9 affective grid. This paper aims to identify specific stress region(s) in the VA space by combining self-reported ratings (pairs of VA) and physiological signals (skin conductance). To this end, 31 healthy volunteers participated in an experiment by performing five stressful interaction tasks while their skin conductance was monitored. The selected interaction tasks were most frequently listed as stressful by a separate group of 15 interviewees. After each task, participants expressed their perceived emotional experience using the VA rating space. Our findings show which regions in the VA rating space may reliably indicate self-reported stress that is in alignment with one’s measured skin conductance while using interactive applications. One additional important contribution of this work is the proposed approach for the empirical identification of affect regions in the VA space based on physiological signals.