The System Usability Scale (SUS), developed in the mid 1980s by John Brooke, is a 10-item Likert scale that provides a crude usability index of electronic systems.  In a recent blog, Jeff Sauro of ‘’ provides a useful list of things to know about the scale including issues with scoring (norms and reverse scores) and the impact of confounds on perceived system usability.   Read Jeff Sauro’s article: “10 Things To Know About The System Usability Scale (SUS)