I’m a designer and I’m often surprised that current science has not been able to answer seemingly simple questions such as “what is the most legible typeface for a printed book?” or “what is the best chair for working on a computer?”. The reason for this, I suspect, is that we are measuring the wrong things. When researchers study legibility, they measure recall ability, speed of reading, and other quantifiable stats. The results of these studies often vary and are difficult to replicate. A good typographer doesn’t aim for style, he/she aims to get typography out of the way in order to read a text with minimal distraction. Erik Spiekermann put it succinctly when he said “typography is like air, you only notice it when it’s bad”. I think design will connect to science only when we are able to peek into the brain and see if a person is really concentrated when reading a text, or pleased when he sits down on a really comfortable chair.

This kind of research will bring great dividends in various fields. I can think of anti-depressant medication, architecture, and advertising (perhaps this last one is more controversial).

One may be dismayed to find out that most things in design haven’t been proved conclusively (in a scientific way). There are many reasons for this, but I think it all boils down to the difficulty of measuring how the human mind reacts when interacting with something. What we have nailed down is the effects of those interactions: clickthroughs, purchases, and such. So, when you try to perform an experiment about legibility you usually apply a comprehension test and measure the speed at which the text was read.

In science you should isolate as many variables as possible, but I think in the case of typography there’s just too many factors at play: the content, the medium and the reader introduce too much noise into the experiments.

I think that in the future brain imaging will advance enough to study how much people are able to concentrate with different typefaces. A researcher might give you an essay written in Comic Sans and see your mind wander more often than other subjects reading the same essay in Times.