The visual perceptiveness of irregularity of a tile on tiled walls was influenced by the extent of irregularity and the species of tiled walls. In the former report, we presented the quantitative value(Rmax) corresponding to the magnitude of human sense on irregularity. In this paper, based on the relationship between Rmax, the species of tiled walls and the psychological scale relating to visual perceptiveness, we established another quantitative value(AI) which indicated the visual perceptiveness of irregularity. AI consisted of Rmax, the length of the tile, the width of the joint and the luminance of the tile and joint.
