I am very interested in this topic: Xerox scientist finds meaning in how documents are presented. They develop ways to measure intent and eye-appeal of documents in collaboration with RIT scientists.

Harrington and his colleagues have identified more than 150 measurable value functions, including density of the text, colourfulness of images, regularity of positioning of images, and diversity of font and typeface, that a designer can use to convey the intent of a document. But their research explores the idea that although style is measured in a large number of value properties, those can be clustered into a relatively small number of intents.(...) With document layout a key means of expressing intent, the scientists considered rules for automating document layouts. They sought objective formulas that could be used to calculate the aesthetics of a document no matter where it appeared.

Among the quantifiable factors they found that could produce aesthetically pleasing layouts were alignment, regularity, uniform separation, balance, proportion of white space, height to width proportion, uniformity and "page security" - the positioning of small objects so they don't appear to be falling off a page