csv << ["#{study_name} ID", "Study ID", "Method", "Event", "Item Bank", "Theta", "Standard Error", "Timestamp"]

assessments.each do |assessment|
  assessment.results.each do |result|
    csv << [
      assessment.stream_id,
      assessment.study_id,
      assessment.method_applied,
      assessment.event,
      result.name,
      result.theta,
      result.standard_error,
      result.updated_at,
    ]
  end
end