Critical View of Data Viz Eye Tracking

Data viz expert Stephen Few looks at work done by Tableau using eye tracking methods to get insight about designing data visualizations.    I recall seeing some previous research in this area.   It is not too unlike similar work being done tracking how people look at advertising or placement on store shelves.   Where do people look, what do they see, what do they retain,  is what we think is important even noticed?   Stephen Few points out the issues.