Proportion and rate have multiple and overlapping meanings, which blur their concepts. Based on the existence of the states and the occurrence of the events and their measuring process, we first put forward the concept of "cumulative number of states in point time". Considering the general meaning of "rate" in mathematics and the units of the elements in indexes, this paper puts forward the concept of "the change of cumulative number of states in point time", which is equal to the commonly acknowledged concept "number of incident event within observation period" or "absolute rate", and further constructs relative rate and proportion. Proportions can be classified into three types: time-point (or rate-type) constitutional proportion, time-period incidence proportion and their synthesis, time-period constitutional proportion. The essential difference between relative rate and time-period proportions is whether the observation period is regarded as a one-unit-length fixed period which would be further moved to the description of the indexes. Furthermore, the sources populations of relative rate and proportions are exclusively those at the beginning of the observation period. Thus, we established a unified identification route about ratios, proportions, and rates, the basic indicators of categorical data in populations. These are applicable to both fixed and dynamic populations. The paper aims to clarify the connotation of the indexes and the feasible understanding route and provide some reference for the population researchers.
比例和率的含义多重而交叉，这模糊了其概念的准确性。本文围绕事件的发生和状态的存在及其测量过程，首先指出了二者的计数有统一的基础——状态，提出了“时点状态累积数”的概念。基于数学上“率”的一般含义，结合指标计算元素的单位，提出了“时点状态累积数的变化量”即通常认为的“（观察期）事件发生数”或“绝对率”，并建立了相对率和比例。比例有3种类型：时点（或率型）构成比例、时期发生比例及由前二者综合而成的时期构成比例。相对率和时期比例的区别在于观察期是否被视为一个观察单位并移位，与时点比例的来源人群均为观察期起点人群。由此本文建立人群分类资料基本指标——比、比例和率统一的识别路线。这些论述同样地适用于关闭队列、固定队列或动态人群。本文旨在明确指标的内涵及可行的认识路线，供人群研究工作者参考。.