Comments on `Parallel algorithms for hierarchical clustering andcluster validity'

In the above-titled paper (ibid., vol.12, no.11, p.1088-92, Nov. 1990), parallel implementations of hierarchical clustering algorithms that achieve O(n²) computational time complexity and thereby improve on the baseline of sequential implementations are described. The latter are stated to be O( n³), with the exception of the single-link method. The commenter points out that state-of-the-art hierarchical clustering algorithms have O(n²) time complexity and should be referred to in preference to the O(n³ ) algorithms, which were described in many texts in the 1970s. Some further references in the parallelizing of hierarchic clustering algorithms are provided