Usability Rating Scale (or URS) to measure perceived effort. The URS is a seven-point scale, with scores ranging from -3 (very difficult) to 3 (difficult). At the top of the scale are the words "Difficult", "Moderate", and "Easy". Branching from each word are the three lines (one in the left diagonal, direction one directly below, and one in the right diagonal direction). All branches point to one or two words, which further clarify how difficult or easy the task was. Below each word is an associated rating from the scale (integers ranging from -3 to 3). The left diagonal line for "Difficult" leads to the words "very difficult", which have an associated rating of -3 below them. The line directly below "Difficult" leads to the words "moderately difficult" and has a rating of -2 below them. The right diagonal of "Difficult" points to the words "barely difficult", which have an associated rating of -1 below them. The left diagonal of "Moderate" also leads to "barely difficult" and the score of -1. The line directly below "Moderate" leads to the word "neither", which has a score of 0 below it. The right diagonal of "Moderate" points to the words "barely easy", which have a rating of 1 below them. The left diagonal of "Easy" also points to "barely easy" and the score of 1. The line directly below "Easy" points to the words "moderately easy" and a score of 2 below the words. The right diagonal of "Easy" leads to the words "very easy", which have an associated score of 3 below them. In this study, after participants performed a transfer, they were asked: "How would you rate your ability to perform the transfer?" To which they would reply, either "Difficult", "Moderate", or "Easy." From there, they were asked to further clarify how easy, moderate or difficult their effort was and the score associated with the clarifying term was recorded. For example, if a participant responded with "Moderate", then they were asked, "Was it barely difficult, barely easy, or neither?" If the participant replied "barely easy", the score would be recorded as 1. If the participant replied "barely difficult", then the score was recorded as -1 and if the response was "neither", the score was reported as 0.