More than Data: A Multivocal Inquiry into Video-Based Research on Learning and Teaching

Purpose This commentary aims to echo Wilkinson, Bailey, and Maher's (this volume) arguments about the affordances of videos and video databases in studying learning and teaching. Design/Approach/Methods This article illustrates a multivocal approach to the videos from the Video Mosaic Collaborative (VMC). In particular, three mathematics teachers in Shanghai were invited to watch and discuss a set of VMC videos. Two recurring themes concerning mathematics learning and teaching were identified in this video-cued interview and discussed in relation to the VMC Analytics. Findings The VMC videos played a mediating and facilitating role in the interview, helping the teachers notice and reflect on the mundane, implicit culture practices. Based upon this analysis, I argue that to tap into the potential of video in educational research, we need to see videos as more than data and look for more possibilities of using them. Originality/Value To open and further research dialogues, this article discusses future directions of using videos in educational research and serves as an invitation to creative explorations, in-depth conversations, ethical reflections, and cross-cultural collaborations on the use of videos in education.

An Improved Video Mosaic Block Detection Method on the Statistics of Pixel Difference across the Boundary of Macroblock and Suspected Mosaic Blocks

This passage proposes a new method to detect mosaic not only using the Y (luminance) component in YUV color space of videos, but also using the U (chrominance) and V component. The mosaic effect is measured by the boundary pixel difference from the neighbor macroblock. Instead of detecting the existence and position of mosaic blocks as traditional methods do, this method focuses on the statistics of the number of suspected mosaic blocks so that the quality of the whole frame affected by mosaic can be assessed. Experimental results show that the new method has good performance on fallout ratio, omission factor and computational complexity.