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Open Access Publications from the University of California

Scholarly Works (2 results)

  • Article
  • Peer Reviewed
IDAV Publications (1999)
Recent interest in data mining and knowledge discovery underscores the need for methods by which patterns can be discovered in data without any proir knowledge of their existence. In this paper, we explore computational methods of finding clusters of multivariate data points when there is no metric given a poriori. We are given an sample, X, of n points in Rp that come from g distinct multivariate normal populations with unknown parameters each of which contributes in excess of p points. Based on the assumption that we are given the number of groups, g, and a computational budget of T seconds of computer time, the paper reviews choices for cluster finding that have been described in the literature and introduces a new method that is a structured combination of two of them. We investigate these algorithms on some real data sets and describe simulation experiments. A principal conculion is strong support for the contention that a two-stage algorithm based on a combinatorial search followed by the EM algorithm is the best way to find clusters.
    Cover page: Some Computational Issues in Cluster Analysis with No A Priori Metric
    • Article
    • Peer Reviewed
    Berkeley Review of Education, Volume 11, Issue 2 (2022)

    To understand the experiences of educators during the 2020 extended school closures, we interviewed 40 teachers from across the country in public, charter, and private schools, at different grade levels, and in different subject areas. Teachers articulated three main concerns about emergency remote schooling: 1.) student motivation; 2.) professional loss and burnout; and 3.) exacerbated inequities. As the climate emergency makes school disruptions more common, school systems must learn from the tragic school closings under COVID-19 to prepare for an uncertain future. We propose five design considerations to build school systems with greater resilience for the long-term: center equity, focus on relationship-building, address student motivation, address staff motivation and burnout, and mitigate uncertainty.

      Cover page: What’s Lost, What’s Left, What’s Next: Lessons Learned From the Lived Experiences of Teachers During the Pandemic
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