Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí hóa học quốc tế đề tài : Discrimination and reliability: Equal partners? | BioMed Central Health and Quality of Life Outcomes Letter to the Editor Discrimination and reliability Equal partners Geoffrey R Norman Address McMaster University Hamilton Canada Email Geoffrey R Norman - norman@ Open Access Published 16 October 2008 Received 6 August 2008 Health and Quality of Life Outcomes 2008 6 81 doi 1477-7525-6-81 Accepted 16 October 2008 This article is available from http content 6 1 81 2008 Norman licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License http licenses by which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. Abstract A critique of Hankins M article How discriminating are discriminative instruments Health and Quality of Life Outcomes 2008 6 36 Letter to the editor There are several definitions of discrimination. Two from the Webster dictionary are 1 the process by which two stimuli differing in some aspect are responded to differently and 2 the quality or power of finely distinguishing. It seems to me that the manuscript by Hankins 1 in attempting to elaborate on 1 shows considerable absence of 2 . To begin with a small disclaimer The McMaster Framework is hardly endorsed by all at McMaster. In fact my co-author Dave Streiner and I both of us originally from McMaster in our textbook 2 specifically challenge the Kirshner and Guyatt 3 notion of different kinds of instruments for different purposes. And now to the matter at hand. Hankins 1 attempts to show that reliability is not a good measure of discrimination and that instruments can be reliable but not discriminating and vice versa. But while he refers to formulas for both reliability and discrimination more on this in a moment he does not actually define either. This is not just pedantry in my view reliability is by definition an index of the ability of an instrument to .