Assessment with visual analogue scales on the Internet
Frederik Funke & Ulf-Dietrich Reips

Paper presented at the 29th International Conference of Psychology ICP 2008
July 20-25, 2008 in Berlin (Germany)

Though visual analogue scales are established instruments and widely used in assessing subjective phenomena in self-administered questionnaires, they are rarely used for surveying large samples. One reason is that in a paper and pencil environment, this way of collecting data takes up a great deal of time as values have to be read out manually. This time is saved in computer-based administration of VAS.
We conducted two Web experiments. The combination of both findings: There is strong evidence that data collected with VAS are equidistant and on the level of an interval scale, while categorical scales produce ordinal data only.