  Rating scales are much used in survey research. Often, it is assumed that the
scores obtained through rating scales can be compared within and between
respondents when studies are in one country. In addition, it is assumed that
they can be treated as a numerical scale. In this paper, we study the anchoring
effect of a visual stimulus on rating scale usage. To do so, we set up a
randomized experiment where the experimental group was primed by asking to rate
the filling of a cylinder that was presented visually. For a five point rating
scale, we find the effect that primed respondents use Category 1 less and
Categories 3 and 4 more, and no effect on Categories 2 and 5.
