[3] Mosaic plots were introduced by Hartigan and Kleiner in 1981 and expanded on by Friendly in 1994.
As with bar charts and spineplots, the area of the tiles, also known as the bin size, is proportional to the number of observations within that category.
The last variable ("Survived") is finally applied, this time along the left edge with the result highlighted by shade: dark grey rectangles represent people that did not survive the disaster, light grey ones people that did.
Similarly, a marginalization over gender identifies first-class passengers as most probable to survive.
The mosaic plot has been criticised for making the data hard to perceive and to compare visually, because the values correspond to areas.