Web Page Layout: A Comparison Between Left- and Right-Justified Site Navigation Menus
http://journals.tdl.org/jodi/article/view/jodi-111/93
  peer-reviewed

Kalbach, James and Tim Bosenick
Journal of Digital Information
2003

Abstract:

The usability of two Web page layouts was directly compared: one with the main site navigation menu on the left of the page, and one with the main site navigation menu on the right. Sixty-four participants were divided equally into two groups and assigned to either the left- or the right-hand navigation test condition. Using a stopwatch, the time to complete each of five tasks was measured. The hypothesis that the left-hand navigation would perform significantly faster than the right-hand navigation was not supported. Instead, there was no significant difference in completion times between the two test conditions. This research questions the current leading Web design thought that the main navigation menu should be left justified.