In Special Issue 8 of 2018 E.M. Van Cott and K.A. Moffat ART (Coagulation Laboratory, Core Laboratory, Massachusetts General Hospital, Boston, USA, Division of Hematology and Thromboembolism, Department of Medicine, McMaster University, Special Coagulation Laboratory, Hamilton Health Sciences, McMaster Division, Hamilton, Canada) described the external quality assessment / proficiency testing for platelet function disorders.