1. A system comprising: one or more computing devices; and a computer-readable medium coupled to the one or more computing devices having instructions stored thereon which, when executed by the one or more computing devices, cause the one or more computing devices to perform operations comprising: receiving a baseline resource, the baseline resource being displayable on a display; rendering the baseline resource as an image to provide a baseline image file including corresponding image data; receiving one or more candidate change resources, each of the one or more candidate change resources including at least one candidate change to the baseline resource, the one or more candidate resources being displayable on the display; rendering the one or more candidate change resources as respective images to provide one or more candidate change image files each including corresponding image data; generating salience maps based on the images; generating simulated eye traces based on the salience maps; and generating additional maps based on the simulated eye traces to determine one or more statistics of interest, the one or more statistics of interest reflecting a user behavior in interacting with a resource.