The measurement of textual patent similarities is crucial for important tasks in patent management, be it prior art analysis,
infringement analysis, or patent mapping. In this paper the common theory of similarity measurement is applied to the field
of patents, using solitary concepts as basic textual elements of patents. After unfolding the term ‘similarity’ in a content
and formal oriented level and presenting a basic model of understanding, a segmented approach to the measurement of underlying
variables, similarity coefficients, and the criteria-related profiles of their combinations is lined out. This leads to a
guided way to the application of textual patent similarities, interesting both for theory and practice.