““Quantitative characteristics” are those where the expression covers the full range of variation from one extreme to the other. The expression can be recorded on a one-dimensional, continuous or discrete, linear scale. The range of expression is divided into a number of states for the purpose of description (e.g. length of stem: very short (1), short (3), medium (5), long (7), very long(9)). The division seeks to provide, as far as is practical, an even distribution across the scale. The Test Guidelines do not specify the difference needed for distinctness. The states of expression should, however, be meaningful for DUS assessment.”
References
UPOV, 2002. General introduction to the examination of distinctness, uniformity and stability and the development of harmonized descriptions of new varieties of plants. https://www.upov.int/export/sites/upov/resource/en/tg_1_3.pdf