2007, Piran, Slovenia

Cognitive and Psycophysiological Function
Table 1. The variability and reproducibility coefficients of the VAS and the LS*
Scale VAS LS
RMSE CV RMSE CV RMSE CV RMSE CV
(N=9) (%) (N=8) (%) (N=9) (%) (N=8) (%)
(N=9)
(N=8)
(N=9)
(N=8)
TTC 16 18.9 12 14.6 0.5 17.1 0.5 16.5
TC 18 19.8 15 15.7 0.5 15.6 0.4 14.9
TTS 12 11.4 10 10.1 0.8 16.6 0.8 15.0
TS 10 8.3 8 6.7 0.5 9.1 0.4 7.7
*The results are displayed in reference to their scales i.e. for the VAS scales the
RMSE is the # of integers on the 160 integer scale. CV= the coefficient of variance.
Stable (0-55mins) vs. Dynamic phases (60-130mins).
For both the scales, the relationships of TS and TC with both T body andT skintorso were
similar for each of the phases examined (stable and dynamic). The exception being
the relationship between TS and T body, where both scales had stronger relationships in
the stable compared to dynamic phase (VAS: r = 0.64 vs. 0.24; LS: r =0.54 vs.0.23, P
< 0.01, respectively). Independent t-tests indicated that the VAS had stronger
relationships with T body ,T skintorso and TC than the LS. This occurred for T skintorso /TC
in both the stable and dynamic phases (r= 0.50 vs. 0.28 and 0.36 vs. 0.22: P < 0.05,
respectively) and TC/T body in the stable phase (r= 0.64 vs. 0.28; P=0.01).
DISCUSSION
Our findings suggest that the VAS were more reproducible than the LS. Two possible
reasons for this are that any change in the LS accounts for 14-25% of the total scale
compared to 0.08% in the VAS. Secondly, VAS are displayed as a 100mm line
labelled at its ends with the “minimum and the maximum descriptor” for a particular
variable, the one used in the present study contains 6-9 descriptors that provide more
reference points.
The relationship between the VAS, LS and physiological variables indicate that the
VAS are at least as valid, and for thermal comfort slightly better, for assessing human
thermal perceptions in stable and dynamic, asymmetric thermal environments than the
LS. Further work is underway to determine the sensitivity of the VAS to human
thermal perceptual changes in dynamic, asymmetric thermal environments.
ACKNOWLEDGEMENTS
The authors wish to express their gratitude to all subjects who participated in the
study. They also wish to thank Julia Allen and Phil Newton for their technical
expertise.
REFERENCES
ASHRAE (1997) ASHRAE Handbook - Fundamentals. Atlanta, ASHRAE Inc. 1997.
Fanger, PO. (1970) Thermal Comfort: Analysis and Applications in Environmental
Engineering. McGraw-Hill, New York.
Zhang, H. (2003) Human thermal sensation and comfort in transient and non-uniform
thermal environments. [PhD Thesis]. University of California, Berkley, CA,
94720-1839, USA.
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