Nikolaos K. Tselios

Context-based design of mobile applications for museums: a survey of existing practices

This paper includes a review of mobile applications used in museum environments, focusing on the notion of context and its constituent dimensions. Museums are a representative example in which the context influences interaction. During a museum visit, the visitors interact with the exhibits through mobile devices. We argue that, effective interaction design needs to take into consideration multiple dimensions of the context. Since context is often misinterpreted, superficially used or poorly defined, we attempt to analyze a number of existing mobile applications used in museum environments, through this perspective. The point of analysis is to evaluate those applications against various context dimensions. We argue that these results can be useful in other kinds of applications, in which the impact of context is not taken for granted.

Development and Evaluation of a Computer-Based Laboratory Teaching Tool

Effective evaluation of educational software is a key issue for successful introduction of advanced tools in the curriculum. This paper focuses on our experience of developing and evaluating a tool for computer‐assisted teaching of engineering laboratory courses. Various categories of educational softwares that can be used for laboratory courses are described. An example of such experimental system is also provided. Finally issues and techniques relating with usability evaluation of instructional software are described with examples of application of these techniques during the design and experimental use of electrical‐machines laboratory educational software.

Perceived usability evaluation of learning management systems: Empirical evaluation of the System Usability Scale

Perceived usability affects greatly student’s learning effectiveness and overall learning experience, and thus is an important requirement of educational software. The System Usability Scale (SUS) is a well-researched and widely used questionnaire for perceived usability evaluation. However, surprisingly few studies have used SUS to evaluate the perceived usability of learning management systems (LMSs). This paper presents an empirical evaluation of the SUS questionnaire in the context of LMSs’ perceived usability evaluation. Eleven studies involving 769 students were conducted, in which participants evaluated the usability of two LMSs (eClass and Moodle) used within courses of their curriculum. It was found that the perceived usability of the evaluated LMSs is at a satisfactory level (mean SUS score 76.27). Analysis of the results also demonstrated the validity and reliability of SUS for LMSs’ evaluation, and that it remains robust even for small sample sizes. Moreover, the following SUS attributes were investigated in the context of LMSs evaluation: gender, age, prior experience with the LMS, Internet self-efficacy, attitude towards the Internet and usage frequency of the LMS.

The effective combination of hybrid usability methods in evaluating educational applications of ICT: Issues and challenges

This paper focuses on usability evaluation of information and communication technologies applications in education (ICTE applications). Various classes of teaching and learning systems are discussed in terms of technologies used and pedagogical approaches. Their usability is analyzed according to various dimensions and the impact of system usability on the learning effectiveness is studied. We argue that various classes of ICTE applications such as multimedia/hypermedia applications, open educational environments and CSCL environments, based on different theoretical perspectives, require fundamentally different approaches in evaluating their usability. The paper is structured as follows: an overview of different usability evaluation approaches is presented first, followed by a discussion on applicability of these techniques in various categories of teaching and learning computer systems. Typical case studies that engage both usability experts and users themselves (students and teachers) are also discussed. The objective is to describe both the methods, and the way to apply them effectively in order to certify the usability of an ICTE application with respect to its teaching and learning objectives.

Website evaluation: a usability-based perspective

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 todays web applications development is also discussed in this paper.

Inferring relations between color and emotional dimensions of a web site using bayesian networks

In this paper, a novel methodology for selecting appropriate color scheme for a web site is presented. The methodology uses a machine learning algorithm for generating a network that relates the color model of a web site with the emotional values that are attributed to it by its users. The approach involves an empirical study to collect data, used to train the algorithm. A preliminary case study has been conducted to validate the applicability of the methodology. Description of the framework and of a set of tools that were built to support the methodology is also included.

Automated semantic elaboration of web site information architecture

Structuring of the content is an important step in web site design, affecting greatly navigability and the overall user experience. Automated support of this task is the object of this paper. AutoCardSorter, a computational tool that supports clustering of the web pages of a site, is introduced. The proposed tool-based methodology uses semantic similarity measures, such as latent semantic analysis, and hierarchical clustering algorithms, in order to suggest suitable information navigation schemes. In the paper, after introducing AutoCardSorter design and functionality, three independent studies are discussed. The studies, that were conducted in order to validate the proposal, compared the proposed method with the established card-sorting approach, in different domains. It was found that substantial gain in effectiveness was achieved without expense in the quality of results, therefore, reducing the required time and human resources.

AutoCardSorter: designing the information architecture of a web site using latent semantic analysis

In this paper, we describe an innovative tool that supports the design and evaluation of the information architecture of a Web site. The tool uses Latent Semantic Analysis and hierarchical clustering algorithms to provide optimal information navigation schemes in an automated manner. The proposed, tool-based, approach addresses the problem of reasonable content structuring, which established techniques such as card sorting also address. A real world case study depicted substantial effectiveness gain, without expense in the quality of results. We argue that such an approach could facilitate information-rich applications design, like most Web sites, by reducing time and resources required.

Improving SMS Usability Using Bayesian Networks

During the last years, the significant increase of mobile communications has resulted in the wide acceptance of a plethora of new services, like communication via written short messages (SMS). The limitations of the dimensions and the number of keys of the mobile phone keypad are probably the main obstacles of this service. Numerous intelligent techniques have been developed aiming at supporting users of SMS services. Special emphasis has been provided to the efficient and effective editing of words. In the presented research, we introduce a predictive algorithm that forecasts Greek letters occurrence during the process of compiling an SMS. The algorithm is based on Bayesian networks that have been trained with sufficient Greek corpus. The extracted network infers the probability of a specific letter in a word given one, two or three previous letter that have been keyed by the user with precision that reaches 95%. An important advantage, compared to other predictive algorithms is that the use of a vocabulary is not required, so the limited memory resources of mobile phones can easily accommodate the presented algorithm. The proposed method achieves improvement in the word editing time compared to the traditional editing method by a factor of 34.72%, as this has been proven by using Keystroke Level Modeling technique described in the paper.

Perceived Usability Evaluation of Learning Management Systems: A First Step towards Standardization of the System Usability Scale in Greek

Perceived usability is an important requirement of educational software, affecting greatly students learning effectiveness and overall learning experience. Although the System Usability Scale (SUS) questionnaire is considered as a de facto standard for perceived usability evaluation, surprisingly, few studies are reporting results from evaluations related to Learning Management Systems (LMSs). In addition, given that the questionnaire comprises 10 questions presented in English, its applicability in studies involving speakers of other languages is questionable. In this paper, a first step towards standardization of a Greek version of SUS in the context of LMSs perceived usability evaluation is reported. To this end, three studies involving 280 university students in both blended and distance learning education were conducted. Analysis of the results demonstrated the validity and reliability of the Greek version of SUS.