The quartet distance[1] is a way of measuring the distance between two phylogenetic trees. It is defined as the number of subsets of four leaves that are not related by the same topology in both trees.
- ^ Estabrook, George F.; McMorris, F. R.; Meacham, Christopher A. (1985). "Comparison of Undirected Phylogenetic Trees Based on Subtrees of Four Evolutionary Units". Systematic Zoology. 34 (2): 193–200. doi:10.2307/2413326. JSTOR 2413326.