Metrological Characteristics of Ordinal Data

• Activity Number: 667
• Type: Contributed
• Date/Time: Thursday, August 5, 2010 : 10:30 AM to 12:20 PM
• Sponsor: Section on Physical and Engineering Sciences
• Author(s): Tamar Gadrich+ and Emil Bashkansky*
• Companies: Ort Braude College and Ort Braude College
• Keywords: ordinal scale ; error ; uncertainty ; repeatability ; agreement ; calibration

Abstract

Although some measurements can be made on any scale (including a continual scale), cost and speed considerations sometimes tip the scales toward using ordinal measurements. This paper presents a way to evaluate classical metrological characteristics, such as error, uncertainty and precision of single and repeated measurements based on the legitimate basic operations for ordinal data. The only legitimate measurement operations among ordinal variables are limited to equal or greater than/less than; the usual assessment measures such as average, standard deviation cannot be applied. Consequently, in order to receive reliable results and draw valid conclusions from ordinal measurements it is essential to develop and use only the appropriate methods. We consider also essential for many applications methods of comparison between two measurement systems.