An assumption in data analysis that when a person is measured on more than one occasion the answers will be the same. Read also the REPEATED MEASURES DESIGN for understanding.

SPHERICITY: "Sphericity is applied to data analysis."
Cite this page: N., Pam M.S., "SPHERICITY," in PsychologyDictionary.org, April 13, 2013, https://psychologydictionary.org/sphericity/ (accessed May 11, 2021).