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",
  // a human-readable (and localized) version of the report_type
  "readable_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,
  // boolean indicating whether the report can be generated, which is true unless
  // the quiz is a survey one
  "generatable": true,
  // 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",
  // the API endpoint for this report
  "url": "http://canvas.example.com/api/v1/courses/1/quizzes/1/reports/1",
  // if the report has finished generating, a File object that represents it.
  // refer to the Files API for more information about the format
  "file": null,
  // 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
  // (Note: not available in JSON-API format)
  "progress_url": null,
  // if the report is being generated, a Progress object that represents the
  // operation. Refer to the Progress API for more information about the format.
  // (Note: available only in JSON-API format)
  "progress": null
}