A Visual Analogue Scale (VAS) is a simple method for measuring subjective experience like mood, pain, or fatigue. Typically, a VAS consists of a 10 centimeter line anchored at each end by words descriptive of opposing statements (bipolar) or the minimal and maximal extremes of one statement (unipolar). On this linear scale, the person indicates how he or
she is feeling at the moment by placing a mark between 2 statements concerning a specific condition of the dimension being measured.
VAS questionnaires are less popular than The Likert scale which is the most widely used scaling technique and commonly used in various stress and health research studies. These scales typically consist of items that for example require respondents to rate their degrees of agreeing or disagreeing with various declarative statements. Usually three to seven response alternatives are used, but there are different opinions about the optimal number of response alternatives.
Many studies compared VAS and Likert scales which share in some cases only 60% of common variance. VAS seems to be more sensitive to smaller changes in subjective states and are not affected by the Wording of the response alternatives as it is the case in Likert Scales. The interpretation of the Visual Analogue Scale with respect what is normal, what is a midrange and what is extreme is left to the test subject.
- Bond & Lader
The Bond & Lader Mood Scale was published 1974 and since then is a widely used clinical scale to measure current mood state, in particular sedative drug effects. In its original version, it consists of 16 bipolar scales that measure four different concepts of mood:
Mental Sedation or intellectual impairment
Physical Sedation or bodily impairment
Tranquillization or calming effects
Other types of feelings or attitudes
To measure more general sleep propensity, the VAS method can also be used to ask single direct questions about specific fatigue dimensions
Aitken, R.C.B. (1969). Measurement of feelings using visual analogue scales. Proceedings of the Royal Society of Medicine, 62, 989-993.
Bond, A., and Lader, M. (1974). The use of analogue scales in rating subjective feelings. British Journal of Medical Psychology, 1974, 47, 211-218.
Hasson, Dan, and Arnetz, B.B. (2005). Validation and Findings Comparing VAS vs. Likert Scales for Psychosocial Measurements. International Electronic Journal of Health Education, 2005; 8:178-192.
Johns, M. (2009). What is excessive daytime sleepiness? in Sleep Deprivation: Causes, Effects and Treatment. Editors; P. Fulke and S. Vaughan. Nova Science, New York, 2009, pp. 59-94