In this study, psychophysics (the subsets of human-centred approach) which includes the perception of slipperiness with visual and tactile cues (Chang et al., Ind Health 52:379380, 2014 [1]) are important to validate human perception of slipperiness. Subject rating was used as an instrument for data collection in human-centred approach. This study measured the perception of four different floor surfaces in five surface conditions—one dry condition and four liquid-spillage conditions. The concerned tested floor surfaces were (i) ceramic I (glazed ceramic tile), (ii) ceramic II floor (unglazed ceramic tile), (iii) epoxy floor, and (iv) porcelain floor (homogenous tile). Chi-square test was used to test the subjective scores of the floor slipperiness while Spearman’s rank correlation coefficient was used to measure the strength of association between the subjective scores of floor slipperiness and the measured COF
