Studying motion with KidVid, a data collection and analysis tool for digitized video

With the support of a grant from the Applications of Advanced Technologies Program of the National Science Foundation, the VIEW project at TERC investigates how to use the power of video to help middle school students learn the mathematical concepts of change over time. Video is an appropriate medium for studying processes that take place over time since it renders transient events permanent, making them available for analysis and replication. By using video as a data collection device, students explore previously inaccessible aspects of the world, such as the motion of animals walking, plants growing, or wheels spinning. Video also provides a means for students to apply graphical, kinesthetic, and linguistic representations of mathematical relationships to obtain more solid understandings of motion. Toward this end, VIEW is designing software tools for students to extract mcasummenta from digitized video. VIEW’s approach is called “Video-Based Labs” (VBL) to emphasize its connection with Microcomputer-Based Labs (MBL) technology, which incorporates probes for light, sound, and motion as on-line data acquisition devices for microcomputers. VBL takes advantage of the following characteristics of videcx ● Video has ubiquitous presence in adolescents’ lives, making it “authentic” and riveting. “ VBL allows students to use video actively, rather than in the passive manner that they usually experience the medium. With VBL they measure, manipulate, and CIWitf3 videos. ● Video can manipulate time, shrinking it (time-lapse) and stretching it (single-frame advance). ● Video can be combined with computer–based measurement instruments and moving images can be displayed with overlayed graphics. ● Video helps students make immediate connections between real–world phenomena and corresponding mathematical representations (e.g. between a video of a Permission to copy without fee all or part of this material IS granted provided that the copies are not made or distributed for direct commercial advantage, the ACM copyright notice and the title of the publ!catlon and its date appear, and notice is given that copying is by permission of the Association for Computing Machinery. To copy otherwise, or to republtsh, requires a fee andlor specific permission. CH194 Companion-4/94 Boston, Massachusetts USA e 1994 ACM 0-89791 -651 -4/94 /0013 . ..$3.50 Dewi Win l-me 2067 Massachusetts Ave. Cambridge, MA 02140, USA Tel: 1-617-547-0430 E-mail: [email protected] person running and the graph of the person’s velocity versus time). “ Video allows the combination of esthetic and mathematical approaches to a topic. = Video appeals to boys and girls and to students of different racial and ethnic backgrounds. With these characteristics in mind, VIEW has designed KidVidTM, an efficient, flexible, and accessible tool that enhances students’ understanding of changeover time. KidVid is an integrated multimedia application that allows students to collect data from a QuickTime@ movie, display it in a table format, and present it in a graphical manner. KidVid is unique because it lets users capture various types of data by clicking a mouse button at different positions and times during a frame-by-frame playback of the video clip cm a computer. The data include art object’s horizontal and vertical positions with respect to a fixed point of reference, and the time stamp associated with the data sample. Fro]m the data, KidVid can derive position and velocity information, and display it in table and graph forms. These representations help students develop ideas about changes in velocity, position, acceleration, and direction. One central pedagogical strand that KidVid incorpmates is the concept of conjecture-making. By conjectures, we mean the articulation of ideas, in some narrative form, relating to the why’s, how’s, and what’s of a mathematical phenomenon. Many of VIEW’s activities are based on the belief that the process of conjecture-making solidifim students’ understanding of ideas because it gives them the opportunity to reflect on and commit to their current understanding of how something changes over time. Once they have communicated their conjectures, students have a basis of comparison for further understanding. KidVid facilitates conjecture-making with its powerful graphing utility. With it, students first sketch velocity versus time or position versus time graphs to convey their predictions about a certain motion scenario that they vidmtape. After discussing the interrelationships between the varying shapes of the graphs and the changing motion of the scenario, students use KidVid to make actual position and time measurements from the video.