The resource has been criticized for the lack of clear structuring principles of the mapping ontology (Lönneker-Rodman 2008).
to date MML is the most comprehensive resource for conceptual metaphor in the linguistic literature, and the examples from the list have been used by computational approaches (Mason 2004;Krishnakumaran and Zhu 2007;Li, Zhu, and Wang 2013), both for development and evaluation purposes.