The definition of primary method of measurement (PMM) of the 'highest metrological quality': a challenge in understanding and communication

Problems with understanding, explaining and communication of the present de finition of primary method of measurement are described and amendments put forward for discussion. The conclusion is drawn that in many cases more att ention should be given to the measurement result and its uncertainty statem ent, rather than to a method. Some cases are discussed where methods might have a fundamental characteristic that other methods do not have, a conditi on for the epitheton 'primary'.