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  1. Our system classifies audio from microphones worn by the teacher in order to determine (1) whether the teacher is addressing the whole class or talking to individuals or groups of students. In the latter case, it determines (2) whether the teacher is giving formative feedback, giving corrective feedback, chatting socially, or addressing administrative or workflow concerns. This paper reports the initial accuracy of this system against human coding of middle school math classroom behavior. We also compared audio collected through professional hardware versus more accessible alternatives.
  2. FACT (Formative Assessment with Computational Technology) is an intelligent orchestration system. That is, because it helps the teacher manage the workflow of a complicated set of activities in the classroom, it is an orchestration system. Because it conducts tasks-specific and domain-specific analyses of the students’ mathematical products and their group interactions, it is more intelligent than other orchestration systems. From analyzing videos of our iterative development trials, we realized that too many students needed help simultaneously, but the teacher could only visit one group at a time. Thus, we modified FACT to send a few messages to the students directlymore »instead of sending all its advice to the teacher. This paper reports a successful pilot test of auto-sending.« less
  3. Collaboration is a 21st Century skill as well as an effective method for learning, so detection of collaboration is important for both assessment and instruction. Speech-based collaboration detection can be quite accurate but collecting the speech of students in classrooms can raise privacy issues. An alternative is to send only whether or not the student is speaking. That is, the speech signal is processed at the microphone by a voice activity detector before being transmitted to the collaboration detector. Because the transmitted signal is binary (1 = speaking, 0 = silence), this method mitigates privacy issues. However, it may harmmore »the accuracy of collaboration detection. To find out how much harm is done, this study compared the relative effectiveness of collaboration detectors based either on the binary signal or high-quality audio. Pairs of students were asked to work together on solving complex math problems. Three qualitative levels of interactivity was distinguished: Interaction, Cooperation and Other. Human coders used richer data (several audio and video streams) to choose the code for each episode. Machine learning was used to induce a detector to assign a code for every episode based on the features. The binary-based collaboration detectors delivered only slightly less accuracy than collaboration detectors based on the high quality audio signal.« less