Warum klassische Evaluation oftmals nicht ausreicht – eine Studie zur Ermittlung der Bedeutsamkeit Mentaler Modelle als Evaluationsmethode

Hohe Benutzertauglichkeit und Akzeptanz eines Webseitenservices sind nur dann gewährleistet, wenn diese auf die funktionalen Bedürfnisse, aber auch auf die strukturellen Vorstellungen ihrer Benutzer zugeschnitten sind. Im Kontext einer Webseite zur „Suche nach E-Learning-Produkten im Internet“ wurde untersucht, inwieweit die Kenntnis der Mentalen Modelle potenzieller Nutzer den Softwareentwicklungsprozess positiv beeinflussen kann. Dabei erlaubte die Erhebung Mentaler Modelle mit Hilfe der Struktur-Lege-Technik (SLT) als Evaluationsmethode einen Vergleich mit der tatsächlich entwickelten Webseite. Die Studie zeigte, dass trotz zuvor bereits durchgeführter, klassischer Evaluationen (Usability Tests, Anwendung von Heuristiken und Cognitive Walkthroughs) 40 Funktionsbereiche genannt wurden, die auf der tatsächlichen Webseite nicht vorgesehen oder umgesetzt sind. Daraus folgt, dass die Erhebung von Mentalen Modellen ebenfalls bereits vor dem Software-Entwicklungsprozess durchgeführt werden soll. (DIPF/Orig.

Building communities for the exchange of learning objects: theoretical foundations and requirements

In order to reduce overall costs of developing high-quality digital courses (including both the content, and the learning and teaching activities), the exchange of learning objects has been recognized as a promising solution. This article makes an inventory of the issues involved in the exchange of learning objects within a community. It explores some basic theories, models and specifications and provides a theoretical framework containing the functional and non-functional requirements to establish an exchange system in the educational field. Three levels of requirements are discussed. First, the non-functional requirements that deal with the technical conditions to make learning objects interoperable. Second, some basic use cases (activities) are identified that must be facilitated to enable the technical exchange of learning objects, e.g. searching and adapting the objects. Third, some basic use cases are identified that are required to establish the exchange of learning objects in a community, e.g. policy management, information and training. The implications of this framework are then discussed, including recommendations concerning the identification of reward systems, role changes and evaluation instruments

GazeTouchPass: Multimodal Authentication Using Gaze and Touch on Mobile Devices

We propose a multimodal scheme, GazeTouchPass, that combines gaze and touch for shoulder-surfing resistant user authentication on mobile devices. GazeTouchPass allows passwords with multiple switches between input modalities during authentication. This requires attackers to simultaneously observe the device screen and the user's eyes to find the password. We evaluate the security and usability of GazeTouchPass in two user studies. Our findings show that GazeTouchPass is usable and significantly more secure than single-modal authentication against basic and even advanced shoulder-surfing attacks

HiER 2015. Proceedings des 9. Hildesheimer Evaluierungs- und Retrievalworkshop

Die Digitalisierung formt unsere Informationsumwelten. Disruptive Technologien dringen verstärkt und immer schneller in unseren Alltag ein und verändern unser Informations- und Kommunikationsverhalten. Informationsmärkte wandeln sich. Der 9. Hildesheimer Evaluierungs- und Retrievalworkshop HIER 2015 thematisiert die Gestaltung und Evaluierung von Informationssystemen vor dem Hintergrund der sich beschleunigenden Digitalisierung. Im Fokus stehen die folgenden Themen: Digital Humanities, Internetsuche und Online Marketing, Information Seeking und nutzerzentrierte Entwicklung, E-Learning

Evaluating Security and Usability of Profile Based Challenge Questions Authentication in Online Examinations

© 2014 Ullah et al.; licensee Springer. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited.Student authentication in online learning environments is an increasingly challenging issue due to the inherent absence of physical interaction with online users and potential security threats to online examinations. This study is part of ongoing research on student authentication in online examinations evaluating the potential benefits of using challenge questions. The authors developed a Profile Based Authentication Framework (PBAF), which utilises challenge questions for students’ authentication in online examinations. This paper examines the findings of an empirical study in which 23 participants used the PBAF including an abuse case security analysis of the PBAF approach. The overall usability analysis suggests that the PBAF is efficient, effective and usable. However, specific questions need replacement with suitable alternatives due to usability challenges. The results of the current research study suggest that memorability, clarity of questions, syntactic variation and question relevance can cause usability issues leading to authentication failure. A configurable traffic light system was designed and implemented to improve the usability of challenge questions. The security analysis indicates that the PBAF is resistant to informed guessing in general, however, specific questions were identified with security issues. The security analysis identifies challenge questions with potential risks of informed guessing by friends and colleagues. The study was performed with a small number of participants in a simulation online course and the results need to be verified in a real educational context on a larger sample sizePeer reviewedFinal Published versio