Ensemble coding, also known as ensemble perception or summary representation, is a theory in cognitive neuroscience about the internal representation of groups of objects in the human mind. Ensemble coding proposes that such information is recorded via summary statistics, particularly the average or variance. Experimental evidence tends to support the theory for low-level visual information, such as shapes and sizes, as well as some high-level features such as face gender. Nonetheless, it remains unclear the extent to which ensemble coding applies to high-level or non-visual stimuli, and the theory remains the subject of active research.