The integration of three field survey datasets in Athens, Greece: transformation of five-point to seven-point thermal sensation scale

The integration of the datasets from three different field surveys on thermal sensation conducted at eight different sites of the area of Athens, Greece was examined. All three surveys were carried out with similar methodologies so data integration can be considered meaningful. The surveys included micrometeorological measurements and questionnaire-based interviews during different seasons focusing on human thermal sensation. The participants self-reported their thermal sensation classified in predetermined classes, i.e. very cold, cold, cool, neither cool nor warm, warm, hot, very hot. However, despite the similarities, one of the surveys used a five-point (±2, ±1, 0) thermal sensation scale whereas the other two a seven-point (±3, ±2, ±1, 0) scale. The present study focused on the transformation of the five-point to a seven-point thermal sensation scale. The middle and extreme classes of both scales were considered to coincide, so the rescaling method involved fitting a common sigmoid curve in all three datasets and reassigning points ±1 of the five-point scale to ±1 and ±2 of the seven-point one. For this purpose, air temperature, grey-globe temperature and Physiological Equivalent Temperature were used as possible independent variables.