Page "Cladogram" Paragraph 23

Homoplasies can often be avoided outright in morphological datasets by defining characters more precisely and increasing their number.

When analyzing " supertrees " ( datasets incorporating as many taxa of a suspected clade as possible ), it may become unavoidable to introduce character definitions that are imprecise, as otherwise the characters might not apply at all to a large number of taxa ; to continue with the " wings " example, the presence of wings would hardly be a useful character if attempting a phylogeny of all Metazoa, as most of these don't have wings at all.

Cautious choice and definition of characters thus is another important element in cladistic analyses.

With a faulty outgroup or character set, no method of evaluation is likely to produce a phylogeny representing the evolutionary reality.