Humans can discriminate trillions of olfactory stimuli, or more, or fewer

A recent Science paper (Bushdid et al, 2014)[1] proposed that humans can discriminate between at least a trillion olfactory stimuli. Here we show that this claim is the result of a fragile estimation framework capable of producing nearly any result from the reported data, including values tens of orders of magnitude larger or smaller than the one originally reported in [1]. We conclude that there is no evidence for the original claim.