Behavior Research Methods

, Volume 40, Issue 3, pp 699–704

Interval-level measurement with visual analogue scales in Internet-based research: VAS Generator

Articles from the Scip Conference

DOI: 10.3758/BRM.40.3.699

Cite this article as:
Reips, UD. & Funke, F. Behavior Research Methods (2008) 40: 699. doi:10.3758/BRM.40.3.699


The present article describes VAS Generator (, a free Web service for creating a wide range of visual analogue scales that can be used as measurement devices in Web surveys and Web experimentation, as well as for local computerized assessment. A step-by-step example for creating and implementing a visual analogue scale with visual feedback is given. VAS Generator and the scales it generates work independently of platforms and use the underlying languages HTML and JavaScript. Results from a validation study with 355 participants are reported and show that the scales generated with VAS Generator approximate an interval-scale level. In light of previous research on visual analogue versus categorical (e.g., radio button) scales in Internet-based research, we conclude that categorical scales only reach ordinal-scale level, and thus visual analogue scales are to be preferred whenever possible.

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Copyright information

© Psychonomic Society, Inc. 2008

Authors and Affiliations

  1. 1.Sozial- und WirtschaftspsychologieUniversität ZürichZürichSwitzerland
  2. 2.University of TübingenTübingenGermany