Today, videos can be replayed on modern handheld devices, such as multimedia cellphones and personal digital assistants (PDAs), due to significant improvements in their processing power. However, screen size remains a limiting resource making it hard, if not impossible to adapt common approaches for video browsing to such mobile devices. In this paper we propose a new interface for the pen-based navigation of videos on PDAs and multimedia cellphones. Our solution -called the MobileZoomSlider -enables users to intuitively skim a video along the timeline on different granularity levels. In addition, it allows for continuous manipulation of replay speed for browsing purposes. Both interaction concepts are seamlessly integrated into the overall interface, thus taking optimum advantage of the limited screen space. Our claims are verified with a first evaluation which proves the suitability of the overall concept.

Distributing recorded classroom lectures via podcasting for replay on mobile devices is gaining increasing popularity. However, few insights exist regarding the actual usage and usefulness of such files, especially in situations where high-quality recordings of those lectures are available for non-mobile replay as well. In this paper, we compare the results of two surveys done with local students who had access to podcasts as well as high-quality files for replay on laptops and desktop PCs on the one hand and external users who just subscribed to the podcasts on the other hand. We compare the usage of the different versions, address the motivations of the two different user groups, and discuss general issues such as perception of the quality of the audio and video signals. Based on our observations we conclude that the added value of such "e-lecture podcasts" is mainly in its potential for mobile usage, whereas most of the other arguments given in favor of such an e-lecture delivery are rather due to the better visibility and "advertisement" of podcasts then justifiable by the technology involved.

In this demonstration, we present a system that enables users to easily generate quizzes for mobile devices. With our program, they can create multiple choice tests and general question-answer pairs by just entering (or copy-pasting) text into an input mask. The text is automatically processed and formatted and corresponding images or text notes are created for representation on an Apple iPod.

PurposePlaying back recorded lectures on handheld devices offers interesting perspectives for learning, but suffers from small screen sizes. The purpose of this paper is to propose several semi‐automatic post‐processing steps in order to improve usability by providing a better readability and additional navigation functionality.Design/methodology/approachSeveral rather simple (and thus fast) statistical indicators were implemented and evaluated to detect certain events in a lecture recording that can be used in a semi‐automatic post‐processing approach.FindingsThe evaluations verify the quality of the analysis. By presenting an actual implementation, the paper demonstrates how these results can be used to improve visibility of the content and provide further navigation options, thus increasing overall usability.Originality/valueThis paper provides practical information on how to build a useful system for everyday usage in normal teaching scenarios. The paper presents different approaches illustrating initial steps for achieving better visualization and navigation functionality for lecture podcast – two issues that are essential for their usability but have not found much attention so far. This implementation demonstrates the usefulness and feasibility of the proposed techniques. Although the purpose of this article is rather on practical aspects than on presenting new research results, some of the observations can have implications for research in this area and some results illustrate important aspects and interesting research opportunities.

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