The perceived amount of white grapes in each of the seven sparkling wines as a function of the participant. Participants 1 to 4 were expert Champagne tasters, participants 5 to 10 had an intermediate level of Champagne tasting experience (shown on a shaded background), and participants 11 to 15 were novice Champagne tasters (though many of them were experienced wine tasters). The actual amount of white grape is plotted by a solid horizontal line (plots ordered so that this increases from top to bottom and from left to right). The mean of the tasters’ responses is plotted by a dashed horizontal line. Nota bene that random participant responses would have resulted in a mean that regressed to 50%, so that random estimates would be more accurate for the Champagnes with approximately 50% white grape.