I appreciate the opportunity to respond to the recent letter by Mokkink et al. (2016). Their letter expressed concerns about a measurement taxonomy developed by Polit and Yang (2016), as described by Polit (2015) in an article in this journal.

The Consensus-based Standards for the selection of health status Measurement Instruments (COSMIN) was an important international effort to clarify concepts relating to measurement (Mokkink et al., 2010). The COSMIN group and its panel of measurement experts are to be applauded for numerous contributions in the field of health measurement, including providing consensus-based definitions of measurement properties, developing checklists for assessing instrument development, and creating the COSMIN measurement taxonomy.