Fig. 1

Item responses for 6 items. The item responses for 6 items are presented for normal (a) and semi-logarithmic (b) scales. a The item responses for each of the 6 items showed a common pattern. The lines for the 6 items crossed between “none” and “a little,” whereas the same lines exhibited a right-skewed pattern between “a little” and “all.” The line of item 4 is hiding behind that of item 6. The responses of Item 4 and 6 are very similar (Table 1). b Using a semi-logarithmic scale, the item responses for the 6 items showed a linear pattern between “a little” and “all”