As a scale, it is a type of ordered-metric scaling that yields a scale with internal reliability, and scale-points in excess of the number of initial anchors, more than would be the case with the Likert scale, though not as many as are achieved by the Analog scale. In Louis Thurstone's tradition, it is scored by paired-comparisons.
This type of scale is ordered and uses paired comparisons to measure reliability. It has more points than a Likert scale but fewer than an Analog scale.