This paper falls within the framework of Formal Concept Analysis which provides classes (the extents) of objects sharing similar characters (the intents), a description by attributes being associated to each class. In a recent paper by the first author, a new similarity measure between two concepts in a concept lattice was introduced, allowing for a normalization depending on the size of the lattice. In this paper, we compare this similarity measure with existing measures, either based on cardinality of sets or originating from ontology design and based on the graph structure of the lattice. A statistical comparison with the existing methods is carried out, and the output of the measure is tested for consistency.