The term "lexicostatistics" is misleading in that mathematical equations are used but not statistics. Other features of a language may be used other than the lexicon, though this is unusual. Whereas the comparative method used shared identified innovations to determine sub-groups, lexicostatistics does not identify these. Lexicostatistics is a distance-based method, whereas the comparative method considers language characters directly. The lexicostatistics method is a simple and fast technique relative to the comparative method but has limitations (discussed below). It can be validated by cross-checking the trees produced by both methods.