“…However, if the categories are expressed in a ordinal scale such as ( ± absent), (¡ equivocal) and (z present), a cumulative chi-squared statistic (x *2 ) has been reported to be more powerful as a test-statistic than a standard chisquared statistic (x 2 ) [14,15]. Hirotsu has applied the cumulative chi-squared statistic to ordered quantitative data as well as to ordered categorical data [10]. For instance, the ordered quantitative data of subjects X and Y are denoted by (x1, x2, x3, x4) and (y1, y2, y3, y4), respectively.…”