1. A method comprising: electronically storing viewing data relating to the viewing of visual stimuli; electronically storing parameters related to the stored viewing data; electronically receiving a first visual stimulus for analysis; electronically matching target parameters for the first visual stimulus with the parameters for the stored viewing data; and if there is a sufficient match between the target parameters with the parameters for the stored viewing data, electronically generating data to represent the first visual stimulus based at least in part on the stored viewing data.