A taxonomy of video lecture styles

Many educational organizations are employing instructional video in their pedagogy, but there is limited understanding of the possible presentation styles. In practice, the presentation style of video lectures ranges from a direct recording of classroom teaching with a stationary camera and screencasts with voice-over, up to highly elaborate video post-production. Previous work evaluated the effectiveness of several presentation styles, but there has not been any consistent taxonomy, which would have made comparisons and meta-analyses possible. In this article, we surveyed the research literature and we examined contemporary video-based courses, which have been produced by diverse educational organizations and teachers across various academic disciplines. We organized video lectures in two dimensions according to the level of human presence and according to the type of instructional media. In addition to organizing existing video lectures in a comprehensive way, the proposed taxonomy offers a design space that facilitates the choice of a suitable presentation style, as well as the preparation of new ones.Comment: 14 pages, 5 figure

User-based key frame detection in social web video

Video search results and suggested videos on web sites are represented with a video thumbnail, which is manually selected by the video up-loader among three randomly generated ones (e.g., YouTube). In contrast, we present a grounded user-based approach for automatically detecting interesting key-frames within a video through aggregated users' replay interactions with the video player. Previous research has focused on content-based systems that have the benefit of analyzing a video without user interactions, but they are monolithic, because the resulting video thumbnails are the same regardless of the user preferences. We constructed a user interest function, which is based on aggregate video replays, and analyzed hundreds of user interactions. We found that the local maximum of the replaying activity stands for the semantics of information rich videos, such as lecture, and how-to. The concept of user-based key-frame detection could be applied to any video on the web, in order to generate a user-based and dynamic video thumbnail in search results.Comment: 4 pages, 4 figure

Taking Social TV Beyond Chatting: How The TV Viewer Adds Value To The Network

In this paper, we provide a comprehensive overview of the state-of-the-art in a contemporary iTV research area: social and networked TV. In our approach, instead of considering research sub-topics that build upon particular disciplinary threads (e.g., usability, personalization, multimedia annotations), we take a multidisciplinary approach that builds upon findings in media studies, human-computer interaction and multimedia systems. Moreover, we downplay the importance of chatting over a distance in favor of non-verbal communication modalities. In contrast, we focus on Social TV practices and highlight the role of each viewer as a node that adds value to the TV network. Finally, we provide directions for further research in neglected topics, such as supporting collocated viewing, and sharing the TV experience in a seamless way

Acquired acid adaptation of Listeria monocytogenes during its planktonic growth enhances subsequent survival of its sessile population to disinfection with natural organic compounds

In this study, the possible influence of acid adaptation of L. (monocytogenes cells during their planktonic growth on their subsequent resistance against some such compounds (i.e. lactic acid, essential oil or hydrosol of Mediterranean spice Satureja( thymbra) nupon their attachment to SS, was evaluated by simultaneously using the bead vortexing technique and a conductance method

P3-21 Comparative Proteomic Analysis of Salmonella enterica serovar Enteritidis PT4 Planktonic and Sessile Cells on Stainless Steel Surface Provides New Insights in Protein Determinants Involved in the Maintenance of a Biofilm community

In order to better understand the cellular mechanisms sustaining a surface-associated lifestyle of S. Enteritidis in food related environments, the differential protein patterns of this bacterium cultivated as biofilm on SS versus planktonic mode were comparatively studied in the present work

Making Sense of Video Analytics: Lessons Learned from Clickstream Interactions, Attitudes, and Learning Outcome in a Video-Assisted Course

Online video lectures have been considered an instructional media for various pedagogic approaches, such as the flipped classroom and open online courses. In comparison to other instructional media, online video affords the opportunity for recording student clickstream patterns within a video lecture. Video analytics within lecture videos may provide insights into student learning performance and inform the improvement of video-assisted teaching tactics. Nevertheless, video analytics are not accessible to learning stakeholders, such as researchers and educators, mainly because online video platforms do not broadly share the interactions of the users with their systems. For this purpose, we have designed an open-access video analytics system for use in a video-assisted course. In this paper, we present a longitudinal study, which provides valuable insights through the lens of the collected video analytics. In particular, we found that there is a relationship between video navigation (repeated views) and the level of cognition/thinking required for a specific video segment. Our results indicated that learning performance progress was slightly improved and stabilized after the third week of the video-assisted course. We also found that attitudes regarding easiness, usability, usefulness, and acceptance of this type of course remained at the same levels throughout the course. Finally, we triangulate analytics from diverse sources, discuss them, and provide the lessons learned for further development and refinement of video-assisted courses and practices

Suburbanization in Greece: The informal transformation of Maroussi into the economic hub of Athens

Greek cities are a seminal part of the Mediterranean urbanization thesis. Corresponding features include the comparatively belated occurrence of urban in-migration, the particularity of the urban pull factors, and the unplanned nature of urban expansion. The considerable and extensive urbanisation wave note in Greece in the post-war period was part of a wider transformative process, characterized by the shifting economic orientation from a prevailing agrarian sector towards urban-industrial economies. The limited manifestation of internal economies of scale in industrial firms, and the few signs of economies of localisation affecting the spatial pattern of industrial development point to the weight of urbanisation as the major factor in industrialisation. In order to maintain and enhance the urbanization/industrialization process, the authoritarian national leadership of the time eased off regulatory planning controls, tacitly facilitating the rapid yet unordered expansion of cities. The conceptualization of the ensuing urban sprawl as an unsustainable trend occurred decades later, following the country?s return to democracy (1974). The path dependent qualities of urban growth management, however, mitigated the effectiveness of the respective efforts. This paper explores the sprawling tendencies of Greek cities, commenting on the limited ability of the regulatory planning framework to influence and direct urban expansion. The Athenian municipality of Maroussi is used as a case in point. Maroussi was a rural area of the Athenian hinterland, turned gradually into the city?s major economic centre. Fieldwork research in Maroussi underscores the informal qualities of Greek suburbanization. The paper is organized in three. The first part discusses the growth of Greek cities in the post-war years, portraying the popular colonization of peri-urban land. The second part outlines the policy changes introduced since the early 1980s, part of an attempt to delineate urban growth. Key amongst them, the launch of a series of state spatial restructuring reforms, aiming to equip local authorities with the necessary means to control urban sprawl. The third part of the paper looks closely at Maroussi, mapping the process and discussing the consequences of an urban expansion mode based on unhindered market forces and unregulated private initiative