Eleftherios Papachristos

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.

Are first impressions about websites only related to visual appeal

This paper investigates whether immediate impression about websites influences only perceptions of attractiveness. The evaluative constructs of perceived usability, credibility and novelty were investigated alongside visual appeal in an experimental setting in which users evaluated 20 website screenshots in two phases. The websites were rated by the participants after viewing time of 500 ms in the first phase and with no time limit in the second. Withinwebsite and within-rater consistency were examined in order to determine whether extremely short time period are enough to quickly form stable opinions about high level evaluative constructs besides visual appeal. We confirmed that quick and stable visual appeal judgments were made without the need of elaborate investigations and found evidence that this is also true for novelty. Usability and credibility judgments were found less consistent but nonetheless noteworthy.

The Subjective and Objective Nature of Website Aesthetic Impressions

This paper explores the possibility to predict positive aesthetic impression and user preference of website design through a combination of objective and subjective factors. The objective factors used are symmetry, order, balance, complexity while the subjective ones include familiarity - novelty ratings. The advantages of such an approach is the reduction of user involvement since the ratings of objective factors may be provided by a small number of design experts. We found indications that balance between certain factors maximize the possibility of users having a positive aesthetic impression.

Modeling perceived value of color in web sites

Color plays an important role in web site design. The selection of effective chromatic combinations and the relation of color to the perceived aesthetic and emotional value of a web site is the focus of this paper. The subject of the reported research has been to define a model through which to be able to associate color combinations with specific desirable emotional and aesthetic values. The presented approach involves application of machine learning techniques on a rich data set collected during a number of empirical studies.

Studying the effect of perceived hedonic mobile device quality on user experience evaluations of mobile applications

When people interact with digital artefacts they perceive their pragmatic and hedonic qualities. In the case of interacting with mobile devices and applications, users seek utility as they try to satisfy certain needs, but at the same time they have certain feelings and emotions when, for example, they feel attached to their personal phone and/or trust its brand. Due to this strong relation between users and mobile devices a significant problem occurs when researchers want to evaluate the user experience of a mobile application in laboratory settings: the selection of an appropriate mobile device. Towards this end, this paper aims to unveil the effect of perceived hedonic quality of a mobile device on the user experience evaluation results of an application. Our results show that the perceived hedonic quality of a mobile device significantly affected the perceived pragmatic quality of the application, but not the hedonic one.

SONETA: A Social Media Geo-Trends Analysis Tool

Social media are used for expressing thoughts and opinions. Finding information hidden inside the vast amount of social media data is an overwhelming task especially for Small and Medium Enterprises SMEs that have limited resources. In this paper, we present an early prototype of SONETA, a social media geo-trend analysis tool that supports users, and specifically SMEs, by helping them detect social media trends in specific geographic areas. First, its architectural design and development process is delineated, followed by the presentation of a study that evaluated SONETA in terms of its usefulness and usability. Three SMEs participated in the SONETA evaluation study. Evaluation results showed that SONETA can be used in order to help SMEs in engaging social media more effectively.

Deployment, Usage and Impact of Social Media Tools in Small and Medium Enterprises: A Case Study

Social media are today engaging millions of users and provide a great venue for various business activities of Small and Medium Enterprises SMEs. However, many SMEs have been slow to adopt them due to perceived barriers such as lack of resources, negative views about their usefulness, and unfamiliarity with technology. Social Media Tools SMTs aim to lift some of these barriers by helping companies monitor, manage and enhance their social media presence. This paper presents a study that investigates the deployment, overall user experience and impact of such SMTs in SMEs. Four SMTs were introduced to three regional SMEs with diverse profiles. The SMEs freely used the tools for a period of one month, and both qualitative e.g. perceived issues and quantitative data e.g. Facebook page fans, Twitter followers were collected before, during and after the study. Evaluation results are presented per SME and common themes are tentatively discussed.

The Influence of Website Category on Aesthetic Preferences

This paper investigates whether users’ aesthetic impressions about websites vary considerably across different domains. The assumption that aesthetic judgments about websites that belong to diverse domains are based on different visual design aspects has been investigated in three distinct studies in healthcare, tourism, and web design business. In these studies participants expressed their overall preference as well as their judgments on the constructs of visual appeal, perceived usability and novelty. In addition, descriptions about the test websites were obtained by expert panel and objective measures. Preference Mapping (PM), which is a data summarization and visualization technique, has been performed in each study. Attribute projection into the preference maps allowed for the identification of important driver of preference for each individual domain. Even though, visual appeal was the most important predictor of overall preference in all studies, appealing websites had different visual characteristics in each domain. Furthermore the importance of the evaluation constructs varied considerably among studies, indicating that aesthetic perceptions differed considerably across domains. These findings emphasize the need for flexible evaluation methods that can be used to identify important visual design factors within a specific website domain.

The application of preference mapping in aesthetic website evaluation

The objective of this study was to apply a technique called preference mapping to the context of aesthetic website evaluation. Preference mapping is a method in which evaluators and stimuli are simultaneously represented in the same multidimensional space. User segmentations and drivers of preference can easily be identified. We argue that this technique is particularly suited for website design evaluation especially for alternative prototype comparisons. The application of this method to an actual dataset resulted in a better understanding of participant preferences that could not be reached through simple comparison of average ratings.