Abstract: An evaluation apparatus comprises a brain wave acquiring unit that acquires a brain wave signal from each of a plurality of subjects; an intensity data generating unit that generates intensity data that represents an intensity of a signal component in a predetermined frequency band or a relation between intensities of signal components in a plurality of frequency bands; a correlation data generating unit that acquires pairs of two subjects for all combinations, calculates a cross-correlation coefficient for the intensity data at each point in time for the respective pairs, and generates, correlation data in the time-series form; and an output unit that generates evaluation data that numerically represents a degree of synchronization of brain wave fluctuation based on the correlation data.