How can I find the information about "characteristics" in xml file?

[zysno1]

Hi, TesterTi

  I am studying the annotation xml about LIDC-IDRI-0002 now. There is a section which named "characteristics" in xml, But I can not found the description about it. 
  For exmple:
  <quote>

    <characteristics>
    <confidence>3</confidence>
    <subtlety>4</subtlety>
    <obscuration>2</obscuration>
    <reason>1</reason>
  </characteristics>  

  </quote>

  What is the meaning of "confidence" and "reason" ? Where can I found these description?

  I have search them at "https://cdebrowser.nci.nih.gov/CDEBrowser/", but nothing be found. 

 Thanks for your help!:)

[TesterTi]

I cannot give too much help on the actual dataset as I was not involved in creating it, but these are additional information related to the markings that the annotators have given. The definitions can be found in the following document: https://wiki.cancerimagingarchive.net/download/attachments/3539039/LIDC_XML_Documentation_1_Jan_2009.doc?version=1&modificationDate=1319224566057&api=v2

"Finally, each reader was asked to subjectively assess several characteristics of the nodule (each characteristic on a 1-5 scale): o Subtlety – in terms of its difficulty in detection o Internal structure – or expected internal composition of the nodule (soft tissue, fluid, fat, air) o Calcificiation – pattern of calcification if present o Sphericity – the three dimensional shape of the nodule in terms of its roundness: o Margin – description of how well defined the margins of the nodule is. o Spiculation – amount of speculation present in nodule o Texture – internal texture or composition of nodule in terms of solid and ground glass components o Malignancy - Radiologist subjective assessment of likelihood of malignancy of this nodule, ASSUMING 60-year-old male smoker"