Fig. 3

Specimen dendogram. Example of a dendogram built from 30 objects whose root stores the value 0.23. This means that the minimum similarity value between any pair of objects is 0.23. The value of 0.35 in the left-hand subtree means that the minimum similarity value between any couple of objects underneath this value (specifically objects 18 to 30) is 0.35. The value of 0.28 in the right-hand subtree means that the similarity value between any pair of objects underneath this value (specifically objects 1 to 17) is 0.28. Once the dendogram has been built, we have to determine how to output the clusters. The usual practice is to establish a cut-off level. For the dendogram in this example, the cut-off level was set at T = 0.45, outputting four clusters, one for each of the branches cut by the line specified by threshold T