Figure 1From: Interpretation for scales of measurement linking with abstract algebraExample of a tree composed of a data set and ordinal arrows. The tree represents changes of states between 17 ‘Rj’s data elements. In ordinal existing methods, data are only a collection of results that are not directly combined; manipulations of parts of the data are defined separately. The arrows merely indicate a change from one state ‘Rj’ to another ‘Rk’ and have no specific operational sense.Back to article page