a series of similar items in which each is almost the same as the ones next to it, but the last is very different from the first 渐变群，梯度变异（群体中相邻的两个成员相差无几，但第一个和最后一个之间差异极明显） Scores are categorized as points along a cline from negative to positive. 分数按从负到正的直线分类。
Word Origin1930s: from Greek klinein ‘to slope’.