A Visual Analog Scale (VAS) is a graphic rating tool used to gauge relativeintensity of subjective measures such as feelings, attitudes, or opinions. A VASconsists of a horizontal line which represents a continuous scale, typically from azero value at left to a maximum value at right. The line is marked at intervals,which may or may not be assigned numerical values or descriptors such as‘Never', ‘Seldom', ‘Sometimes', etc.
Testers or subjects place an ‘x' or other markon the line representing the location of their perceived rating or self-rating. TheVAS shown below has been used to self-report pain intensity.For example, the pain intensity for the subject response below has a VAS value of