AN EVALUATION STUDY OF THE DIAMETER SIZE DISCRIMINABILITY OF NT COINS

ABSTRACT Due to the rapid growth and development of technology, the plastic cash has been a new exchange tool. However, the tradition coin is still a popular exchange tool. This study used the psychophysical method of constants stimuli to determine the difference threshold and Weber Fraction of diameter size of NT coins. A total of 30 college students (15 males, 15 females) participated in the laboratory experiment. A standard diameter size (23 mm) and eight comparison diameter sizes (18, 19, 20, 21, 22, 24, 25, 26, 27, 28 mm) of coins were used. A constant Weber Fraction of about 0.04 and a mean difference threshold of about 0.918 mm at diameter size of 23 mm were found. The effect of gender on the size discriminability was not significant. Furthermore, the diameter size discriminability of NT$20 was confused easily with NT$10. The information obtained in this study will help in improving the design of NT coins.