SUMMARY This paper is concerned with the design and implementation of an innovative user support system in the frame of an open educational environment. The environment adapted is ModelsCreator (MC), an educational system supporting... more
SUMMARY This paper is concerned with the design and implementation of an innovative user support system in the frame of an open educational environment. The environment adapted is ModelsCreator (MC), an educational system supporting learning through modelling activities. The pupils' typical interaction with the system was modelled using Bayesian Belief Networks (BBN). This model has been used in ModelsCreator to build an adaptive help system providing the most useful guidelines according to the current state of interaction. A brief description of the system and an overview of application of Bayesian techniques to educational systems is presented together with discussion about the process of building of the Bayesian Network derived from actual student interaction data. A preliminary evaluation of the developed prototype indicates that the proposed approach produces systems with promising performance.
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ModellingSpace is a learning environment that allows collaboration of partners, collocated or at a distance in various educational settings. This paper describes the main features of the architecture of the ModellingSpace environment and... more
ModellingSpace is a learning environment that allows collaboration of partners, collocated or at a distance in various educational settings. This paper describes the main features of the architecture of the ModellingSpace environment and in particular issues related with coordination and communication during problem solving. The results of an evaluation study of ModellingSpace, which has been recently contacted in order to
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ABSTRACT This paper presents the conceptual and architectural design of a multilayered framework aiming to provide a two handed gesture based visual interactive 3D object oriented environment for software development. We argue that this... more
ABSTRACT This paper presents the conceptual and architectural design of a multilayered framework aiming to provide a two handed gesture based visual interactive 3D object oriented environment for software development. We argue that this is a viable, intuitive and attractive approach for software development facilitating natural human computer interaction, thus supporting tasks related to software development in a more effective and efficient way. We illustrate the value of the proposed environment through a data analysis from early evaluations of one prototype system in use. The results and implications of this study are useful for designing effective and efficient gesture based 3D interactive software development environments.
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Abstract. This paper discusses the effect of learning material heterogeneity on real-time computersupported collaborative problem solving. A study has been contacted in the frame of an authentic educational activity in a Greek secondary... more
Abstract. This paper discusses the effect of learning material heterogeneity on real-time computersupported collaborative problem solving. A study has been contacted in the frame of an authentic educational activity in a Greek secondary school. The students involved were provided with sets of primitive resources of varying degrees of heterogeneity to be used during collaborative modelling activities. Analysis of students peer interaction and produced solutions revealed that, contrary to our expectations, the group with heterogeneous ...
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Abstract. The need for peer-to-peer collaboration over the Internet is increasing nowadays. There are many factors that make this task particularly difficult. Software designers and developers often come across the challenge of overcoming... more
Abstract. The need for peer-to-peer collaboration over the Internet is increasing nowadays. There are many factors that make this task particularly difficult. Software designers and developers often come across the challenge of overcoming the raising technical and organizational problems. These problems include mostly the limited bandwidth of networks especially of dialup connections, but also the presence of firewalls and proxy servers in intranets that inhibit peer-to-peer communication. A flexible architecture needs to be ...
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SUMMARY This paper discusses human-computer interaction in the context of collaboration-support environments. In particular our experience with the design and experimentation with tools to support collaborative problem solving is... more
SUMMARY This paper discusses human-computer interaction in the context of collaboration-support environments. In particular our experience with the design and experimentation with tools to support collaborative problem solving is described. Alternative design options are studied and their effect on synchronous collaboration at a distance, through observation of users' performance is discussed. The use of collaboration analysis tools, which have been developed in the frame of this research is also outlined. KEYWORDS: Collaborative ...
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Computer-supported collaborative problem solving requires new methodological approaches of interaction and problem solving analysis. Usually analysis of collaborative problem solving situations is done through discourse analysis or... more
Computer-supported collaborative problem solving requires new methodological approaches of interaction and problem solving analysis. Usually analysis of collaborative problem solving situations is done through discourse analysis or interaction analysis, where in the center of attention are the actors involved (students, tutors etc.). An alternative framework, called" Object-oriented Collaboration Analysis Framework (OCAF)" is presented here, according to which the objects of the collaboratively developed solution become the ...
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Abstract In this paper a context-aware service for synchronous support in Web-based educational systems is proposed. The main purpose of the service is to support Web-based learning scenarios by allowing synchronous communication and... more
Abstract In this paper a context-aware service for synchronous support in Web-based educational systems is proposed. The main purpose of the service is to support Web-based learning scenarios by allowing synchronous communication and interaction among the tutors and the students, thus increasing the communication channels among them. Furthermore, the service provides a variety of tools that allows the tutors to provide real-time support to the students, discover usability and navigability problems and monitor their ...
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In this paper we present the model-checking module of decision-making models in the frame of ModelsCreator, an educational modelling environment. The model-checking module aims to assist young students to construct qualitative models for... more
In this paper we present the model-checking module of decision-making models in the frame of ModelsCreator, an educational modelling environment. The model-checking module aims to assist young students to construct qualitative models for decision-making problems solving. We specify the decision-making models that may be built and we explain the model checking mechanism. The model-checking mechanism compares the student model with the reference model constructed by the teacher and provides immediate advice to the student to help him create a valid model. So, the model-checking module of a decision-making model aims to facilitate student to structure convincing decisions in the proper situations.
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This paper presents the main characteristics of Logic Models Creator (LMC). LMC is a new educational environment for young students to build and explore logic models in graphical form. LMC allows visual representation of logic models... more
This paper presents the main characteristics of Logic Models Creator (LMC). LMC is a new educational environment for young students to build and explore logic models in graphical form. LMC allows visual representation of logic models using IF/THEN/ELSE constructs. In this paper we provide an overview of LMC architecture and discuss briefly an example of use of LMC. As discussed, LMC users in the reported case study managed to achieve effective communication and task evaluation during exploration of problems involving decision making.
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The usability is recognized as an important quality factor of any modern website. In this paper, techniques for usability evaluation of a website are proposed and their use is described. The results of application of these techniques are... more
The usability is recognized as an important quality factor of any modern website. In this paper, techniques for usability evaluation of a website are proposed and their use is described. The results of application of these techniques are discussed in the frame of the design and evaluation of a web portal, serving an Academic Department. The applicability of the developed techniques in a wide area of web-based applications and their importance in the context of today’s web applications development is also discussed in this paper.
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Effective and efficient methodologies are essential for developing and maintaining information systems that are both secure and usable, especially in the case of Internet applications that require a combined effort from application,... more
Effective and efficient methodologies are essential for developing and maintaining information systems that are both secure and usable, especially in the case of Internet applications that require a combined effort from application, system, network, security, and human-computer interaction design areas. In this paper, we propose a user-centric approach towards achieving "usable security". As a case study we apply the proposed approach on the password management problem. Our work demonstrates that the "user-centric usable security" is a viable and promising future research direction.
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The paper studies undergraduate students' synchronous peer interaction using a shared Activity Space and a text communication tool. Several groups of students collaborated in order to accomplish a data-modelling task in the context of a... more
The paper studies undergraduate students' synchronous peer interaction using a shared Activity Space and a text communication tool. Several groups of students collaborated in order to accomplish a data-modelling task in the context of a Databases University undergraduate course. The paper presents the collaboration support environment, i.e. a concept-mapping tool, used in this study. Subsequently, evaluation of the effectiveness of the environment in the educational process is discussed along various dimensions, like group synthesis, task control, content of communication, roles of the students and the effect of the tools used. Special emphasis is given in the ways the tools and the representations used complement each other and support the process. A discussion on the use of computer-supported collaborative problem solving environments is also included.
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Logic reasoning presents notable difficulties for young children. This paper presents Logic Model Creator (LMC), a new environment that supports building and exploration of intuitive visual representation of logic models by young... more
Logic reasoning presents notable difficulties for young children. This paper presents Logic Model Creator (LMC), a new environment that supports building and exploration of intuitive visual representation of logic models by young children. LMC logic models are structured as hypothesis, decision and / or counter decision components. These models are built using visual entities which represent the learning concepts of a specific domain. In this paper we focus on the architecture of LMC and the basic functionality of the environment. In particular we describe the the dynamic creation of equivalent logic models according to the so-called Reference Logic Model, constructed by the students’ tutor. Furthermore an assessment module which provides immediate advice to the student in order to help them create a valid logic model is presented. Through experimentation it is demonstrated that the users of LMC can have rich interaction and assessment while exploring decision making logic constructs.
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Abstract Text passwords are commonly used for user authentication in the web. There is lately a strong interest for case studies on the password habits of populations with different cultures and/or languages. In this paper, we augment the... more
Abstract Text passwords are commonly used for user authentication in the web. There is lately a strong interest for case studies on the password habits of populations with different cultures and/or languages. In this paper, we augment the existing literature with a case study of Greek web sites. We analyze clear text and encrypted passwords for almost 19,000 accounts and we draw conclusions on similarities with and oppositions to alike empirical studies. Our findings indicate that a significant percentage of users chooses easily- ...