title: Modelling errors in scoring the darkness of staining.
abstract: OBJECTIVE
  To construct a statistical model for the agreements and disagreements between two observers on darkness of staining.
  
  
  METHODS
  Data from an earlier observer-agreement study by van Diest et al were reanalyzed.
  
  
  RESULTS
  A model in which the random variation in error is permitted to depend upon the true darkness of staining wasfound tofit the data much better than does one in which the random variation is constant.
  
  
  CONCLUSIONS
  For the dataset analyzed, error tends to be greater (that is, correlation between observers tends to be less) when staining is darker.
authors.affiliation: Department of Psychology, Macquarie University, Sydney, NSW, Australia. phutchin@bunyip.bhs.mq.edu.au
authors.forename: T Paul
authors.initials: TP
authors.lastname: Hutchinson
authors.forename: Sigurbjorg
authors.initials: S
authors.lastname: Gudlaugsdottir
mesh_terms: D001943:Breast Neoplasms / Q000145:classification / Q000473:pathology; D002467:Cell Nucleus / Q000145:classification / Q000473:pathology*; D003627:Data Interpretation, Statistical; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D015233:Models, Statistical; D015588:Observer Variation; D015203:Reproducibility of Results; D013194:Staining and Labeling