"...the book represents a formidable contribution to psychology where the discipline is taken to be a science on a par with physics, and hence in line with a historically strong position in psychology but one currently on the wane."—British Journal of Mathematical and Statistical Psychology"In my opinion this is one of the most important volumes on the foundations of science to appear during my career, and I venture to guess that it will stimulate much critical discussion both at philosophical and scientific levels."—R. Duncan LuceUniversity of California at Irvine"This monograph may be a milestone of the 21st century because it examines so thoroughly the basis for measurement....The topic is one of the most fundamental in science but often not well understood by scientists themselves. It is a particularly important aspect of psychology and economics."—Stephen LinkVisiting Scholar, University of California at San Diego