visual analog scales

A visual analog scale (VAS) is a tool used to measure subjective feelings or sensations, like pain or discomfort. It typically appears as a straight line, usually 10 centimeters long, with descriptors at each end (for example, "no pain" and "worst pain imaginable"). The person marks a point on the line that best represents their experience. The position is then measured to quantify their perception, providing a simple yet effective way to capture personal intensity levels. VAS is widely used in healthcare and research to assess changes over time or responses to treatments.