Up to the present time, there have not been many studies carried out to determine an effective method for systematical conditional setting for polka-dot patterns, because most previous studies have used commercial printed polka-dot patterns. Therefore, we prepared thirty samples with different patterns wherein two kinds of patterns (i.e., an oblong and a square) each with polka-dot diameters of 1.6, 1.4 and 0.8 cm were respectively combined with five different colors by means of CG (computer graphics). In addition, in these samples, area ratios of the polka-dots to the background area were consistently maintained at 1 : 7 for the rectangular pattern and at 1 : 5.8 for the square pattern.
Characteristic values of these samples were obtained by means of optical measurements and a sensory evaluation to try to determine those factors, which controlled images expressed by the polka-dot patterns set in different conditions. The following results were objectively proved.
1. From the results of the SD method, a more significant distinction was found in the evaluation of color samples of different color values for each polka-dot size than in that of different dot sizes on each color sample.
2. From the results of the t-test, a more significant distinction was found in the evaluation of the two design patterns in the case of the polka-dot diameter of 1.6 cm. In addition, it was found that yellow and green had relatively profound effects on the arrangement of the polka-dots.
3. It was also proved by the method of paired comparison that the variation of polka-dot colors distinguished more remarkably differences in pattern images than their sizes did.
4. From the results of the method of paired comparison, for most of the evaluation items, values of evaluation in the case of oblong patterns were higher than those in the case of square patterns.
5. There was a correlation between visual evaluation and relative value and chrome on polka-dot patterns.
It was found that the sensory test is quite an effective way to study polka-dot patterns.
