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Repost: "20 Questions" requirements gathering

Jim Gray, a Turing award winning computer science researcher at Microsoft Research, has used a "20 questions" methodology to gather data management requirements from scientists in Astronomy, Ecology, Materials Engineering, and more. Each of these efforts led to very successful projects.

The idea is this: You all, collectively, provide 20 science questions about your data that are difficult or cumbersome to answer using existing software. I take those 20 questions and your data and design an online system that can answer each one.

For example, for the Sloan Digital Sky Survey project, the astronomers provided the following questions about their telescope data (among others):

  1. Find all galaxies without unsaturated pixels within 1' of a given point of ra=75.327, dec=21.023
  2. Find all galaxies with blue surface brightness between and 23 and 25 mag per square arcseconds, and -10
  3. Find all galaxies brighter than magnitude 22, where the local extinction is >0.75.
  4. Find galaxies with an isophotal surface brightness (SB) larger than 24 in the red band, with an ellipticity>0.5, and with the major axis of the ellipse having a declination of between 30” and 60”arc seconds.
  5. Find all galaxies with a deVaucouleours profile (r¼ falloff of intensity on disk) and the photometric colors consistent with an elliptical galaxy. The deVaucouleours profile
  6. Find galaxies that are blended with a star, output the deblended galaxy magnitudes.
  7. Provide a list of star-like objects that are 1% rare.
  8. Find all objects with unclassified spectra.
  9. Find quasars with a line width >2000 km/s and 2.5
  10. Find galaxies with spectra that have an equivalent width in Ha >40Å (Ha is the main hydrogen spectral line.)
  11. Bill


    Alexander S. Szalay, Peter Kunszt, Ani Thakar, Jim Gray, Don Slutz, Robert J. Brunner, Designing and Mining Multi-Terabyte Astronomy Archives: The Sloan Digital Sky Survey, Technical Report, MS-TR-99-30

    Jim Gray; Alex SzalayWhere the Rubber Meets the Sky: Bridging the Gap between Databases and Science, Technical Report, MSR-TR-2004-110