The Effects of Line Length and Text Justification on Reading Online

A new study published by Usability News reveals very interesting information:

Passages formatted with 95 characters per line result in faster reading speed when compared to passages formatted with 35, 55, or 75 characters per line. At the same time 55% of the study participants chose 95 characters per line as the least preferred line length. No effects of line length were found for comprehension or satisfaction. The passages used Arial 10-point font with 12-point interlinear spacing between lines, exactly like this paragraph uses.

According to the second study “Is Multiple-Column Online Text Better? It Depends!”, people read one-column left-justified text much faster that one-column full-justified text, while comprehension is pretty much the same for both layouts.