Statistics is a science that studies the mass phenomena occurring in society in terms of quality and quantity. This is just one of the accepted definitions. There is a point of view on it, as a science that develops statistical methods for research, which are carried out in various fields.
The most essential and general signs, properties, connections of phenomena and objects existing objectively reflect certain concepts or categories. With their help, this science studies its own subject. One such category is a statistical population. This is a large number of changing phenomena that exist in space and in time. All of them are relatively homogeneous and have signs that bring them together or distinguish.
The statistical population is characterized by the following properties:
- Indecomposability. When some elements of a statistical population appear or disappear, its qualitative basis is not destroyed. For example, the characteristic of the community of students does not change from the fact that every year freshmen enter its ranks, and graduates leave them.
- Homogeneity. A statistical population always has at least one common attribute for all its elements. And at the same time, this property is not the same for them. This characteristic may have different meanings for different units. The extent to which the population is uniform is established during the study. And this property depends, first of all, on those goals and tasks with which it is carried out.
- Variation. This property is more important than the previous two. It manifests itself as follows: during the transition from one element of the statistical population to another, the quantitative value of the attribute changes. It may be the same for all components. In this case, in order to get an idea of what a statistical population is, you can not study it completely, but consider only one constituent element. A variety of causes and conditions affect the occurrence of variation. Their finding, clarification engaged in economic disciplines. And statistics only evaluate from a quantitative point of view how each cause affects the variation of a particular trait. Information about this helps to make the right management decisions.
Statistical aggregates are divided into several groups:
- Those that are created by life. They already form a unity, regardless of whether they are being investigated or not. This, for example, the aggregate of industrial enterprises of the city, the aggregate of their workers. They really exist, they can be measured.
- Groups that are formed specifically to conduct research. This, for example, is a statistical population of readers of a certain periodical.
- Hypothetical sets. These are stochastic aggregates (for example, celestial bodies existing throughout the galaxy). That is, they are only supposed to be thought.
Any statistical population belonging to any of the three groups has characteristic features. They can be classified for many reasons.
For example, depending on the nature of the expression, the signs are:
- Descriptive (attributive). They are expressed using words (for example, education, nationality, gender). These features make it possible to summarize how many units have one value or another.
- Quantitative. Their measure is numerical (for example, age, length of service, income or expense, etc.). These features also allow you to summarize the number of those units that have a certain value, as well as their average or total value separately for the aggregates.