Yesterday I replied to a posting in the Dutch Usenet group on web design (nl.internet.www.ontwerp) with a link to an article on the optimal line length when reading prose text from a monitor, published in the UI Design Newsletter of November, 2002. I had found this article quite some time ago, and considered it an interesting read and hence it ended up in our local wiki, which Esme and I use to store our bookmarks and other useful notes.
Warden Dave, one of the regulars of the Dutch web design Usenet group replied with a link to another very interesting article: "The Effects of Line Length on Children and Adults? Online Reading Performance", Usability News, 4.2 2002. I am very interested in this topic since I have plans for redesigning this web site and want to learn more about how people read on line.
I also was wondering how strong those preferences could be learned by reading books and news papers, especially since the UI Design Newsletter concludes that:
Users tend to read faster if the line lengths are longer (up to 10 inches).
But also that:
Finally, users tend to prefer lines that are moderately long (4 to 5 inches).
The article in Usability News concluded that:
For adults, it is suggested that medium line lengths should be presented (approximately 65 to 75 CPL). Children, on the other hand, indicated their preference for the narrowest line length (45 CPL) and, thus, it may be beneficial to use narrow line lengths when possible.
All in all a lot of interesting information and quite some to think about.