Hi Liviu, I can't help but weigh in on this one. I think it really depends on who the audience is, how much they are motivated, and the medium through which you are delivering the message.
> My personal experience from the bench suggests something similar. > Whenever I spend too much time trying to figure out what was written > (say, on the blackboard) I have much less time to focus on what was > meant. This is my experience as well. Making a lecture or presentation difficult to understand is a terrible, terrible idea. Verbal communication is already inefficient (people speak much slower than they read) and our "working memory" for speech is smaller than it is for written text. Combine it with the fact that people can only focus on one thing at a time and you have disaster. If you become distracted reading text and miss what the speaker is saying, , you might miss something important. If that something important is part of the logical chain of the argument (say you missed an important step in the derivation of a formula), it can greatly change how you understand everything that comes afterward. These limitations are mitigated by the fact that presentations are interactive, which means that a good presenter can repeat and gauge the understanding of the audience in real time. With written text, there is the advantage that you can deliver much more information and provide it at much higher resolution than you ever could in a presentation. If there is a point of confusion, the reader simply returns to re-read earlier passages. But density can also have its problems. If the words on the page appear too dense, people will refrain from reading them unless there is some motivation to do otherwise. It's important to note that it doesn't actually matter what the words say, if the line length is too long, or the word forms appear convoluted, or the layout is poor, it all has the same effect. This paper does a pretty good job of discussing the ways that different layout features influence letter detection and readability. Denis G. Pelli et al., “Feature detection and letter identification,” Vision Research 46, no. 28 (December 2006): 4646-4674. if you can't access the message of the article, it doesn't really matter what it says. I agree with one point in the economist article, it is good to make people think deeply about things. Challenging the mind and forcing it to process information will result in long-term retention. All of the study's observation can probably be explained by one thing: the slightly more difficult text caused people to slow down as they read, taking more time to digest But isn't that the point of exercises, engaging stories and other rhetorical devices? But the tolerances for "making the text harder to read" are probably so narrow, that the technique may as well be worthless. At what point does effective become convoluted? In all of his books, Tufte makes the point that "dense" does not mean "well designed." I think it better to achieve the same result through other means. Striking examples, well drawn illustrations, anecdotes, intelligent graphs can all accomplish exactly the same thing while keeping the text clean and readable. The goal should be to focus attention, not create additional work. Just my two cents, though. Cheers, Rob
