A QuizReport object looks like:

{
  // the ID of the quiz report
  id: 5,

  // the ID of the quiz
  quiz_id: 4,

  // which type of report this is
  // possible values: "student_analysis", "item_analysis"
  report_type: "student_analysis",

  // boolean indicating whether the report represents all submissions or only the most recent ones for each student
  includes_all_versions: true,

  // boolean indicating whether the report is for an anonymous
  // survey. if true, no student names will be included in the csv
  anonymous: false,

  // when the report was created
  created_at: "2013-05-01T12:34:56-07:00",

  // when the report was last updated
  updated_at: "2013-05-01T12:34:56-07:00",

  // if the report has finished generating, a File object that
  // represents it. refer to the Files API for more information
  // about the format
  file: {
    content-type: "text/csv",
    url: "http://www.example.com/files/123/download..."
    // ...
  },

  // if the report has not yet finished generating, a URL
  // where information about its progress can be retrieved.
  // refer to the Progress API for more information
  progress_url: null
}