Statistics is a science that, using probability calculations, studies collective phenomena and processes (social, natural, etc.) in quantitative terms, in order to study and describe these phenomena and processes, as well as to discover the laws of their manifestation. By familiarizing yourself with the basic categories and methods of statistics as a science, you can understand how it works.
Statistics help to obtain the necessary information from the available data volume, which can be quite large. Information can be used to understand available data (descriptive statistics) or to discover new information about events and their relationships (logical statistics).
Types of statistics share the basic concepts and categories of statistics. It is practically impossible to summarize them, since this discipline operates with huge volumes of data, methods and principles of their processing.
The process of obtaining information from the data is called a statistical conclusion about some statistical parameters or even entire probability distributions. This is a more general view adopted by nonparametric theory in statistics.
In classical applied statistics, the subject of statistics and the main categories of statistics (summarized below) are more clearly defined, therefore it is preferable to build a statistical model with which to draw conclusions; in most cases, this model is not tested, which can lead to erroneous conclusions.
Statistics as a science is widely used by other branches of science, such as physics, biology, psychology, economics, sociology and others.
Sources of statistics
To learn as much as possible about phenomena and processes, including economic and social ones, as well as to determine patterns and relationships using statistical methods and techniques, you must first characterize and describe the current situation as accurately as possible. This is done by collecting data that reflects the actual state of affairs, that is, by statistical observation.
The necessary data can be obtained from various sources:
- from specially organized statistical studies, these are primary data (for example, census or survey results);
- from the existing information system (for example, from current records of economic agents, banks and various databases of some central and local government institutions) - such data is called secondary.
For example, in September 2008, the General Directorate of Regional Statistics in Bucharest published a statistical bulletin for the second quarter of 2008: natural migration of the urban population, income of workers, number of unemployed, basic industrial goods produced in Bucharest, the dynamics of trade for enterprises with primary activities in the retail sector and market services and more. All this published information is a secondary source of statistics.
Statistical observation: content, necessity, tasks
Statistical data - one of the basic concepts and category of statistics - is necessary in order to start the process of proper statistical research to assess the effectiveness of social and economic processes, to formulate alternative ways of making decisions, etc. Thus, the data can be considered as necessary information for generating judgments about decisions in specific situations.
For statistical analysis to be useful for decision making, the input must be correct and consistent with the goal. Therefore, determining the necessary data and how to collect it is extremely important. That is why it is important to know the subject of statistics, the main categories of statistics and its methods
If there are errors in the data, if they are ambiguous and misleading, even the most sophisticated and complex processing methods will be ineffective and will not be able to compensate for the shortcomings; it is obvious that the results in this case will not be correct and useful.
Any process of statistical research begins with statistical observation. This is part of the main categories of statistics as a science. The method of its organization and conduct additionally affects other stages of the statistical research process, since obtaining reliable, real, accurate data determines the quality of the stages of processing, analysis and interpretation of the results.
Statistical observation is the first stage of a statistical study, which consists in a systematic and unified collection and registration of statistical data for all indicators included in the research program.
Surveillance must comply with quantitative and qualitative requirements:
- the fulfillment of quantitative conditions (the required amount of data) means the receipt in a predetermined time of the entire amount of data necessary to achieve all the goals of the statistical study;
- fulfilling the quality conditions guarantees the authenticity of the data collected, so that the results obtained by processing this data are as accurate as possible and lead to the adoption of the most correct decisions.
If statistical research is required to obtain statistical data, then it should be carried out in accordance with a certain plan in order to ensure the most accurate and relevant results with minimal material and financial resources.
Statistical Surveillance Plan
Statistical observation does not happen randomly, because collecting data requires some effort, especially if the goal is to obtain reliable data. Typically, statistical observation relies on a pre-compiled plan (or program) designed in accordance with the purpose of the statistical study.
A complete observation plan, which is based on the subject and categories of statistics, usually includes the following elements:
- purpose of observation;
- object of observation: a set of objects with similar characteristics that are monitored, for example, agricultural firms, engineering enterprises, the population of a city, students or schoolchildren;
- unit of the object of observation: an integral element of the object of observation, the carrier of the main characteristics of the object, that is, a separate company, enterprise, family, etc .;
- time and place of observation;
- identification of the characteristics that are being monitored;
- form for recording data;
- organizational measures and instructions.
The observation plan in the narrow sense contains only a list of all the characteristics that should be recorded, the necessary indicators, etc.
It is worth considering separately the components of the statistical observation plan, since they represent the main categories of statistics.
Purpose of observation
The purpose of the observation is subject to the general purpose of the statistical study and continues to influence all other elements of the observation program. Setting goals to be achieved through research is the starting point for developing a plan.
Study group
At this stage, the determination, establishment of all statistical units that will be included in the study.
This is done using well-known nomenclatures, existing classifications or previous research in the field (if any). The degree of coverage of the observed group depends on the observation method that will be used:
- if this is a general observation method, then the observation object will consist of all units of the group;
- if the partial observation method is used, data will be collected only on the part of the collective units of the group, which will constitute the object of observation.
However, in both cases, for the correct determination of the object of observation, it is necessary to determine the space, time and organizational coordinates of the group of interest.
Unit of observation
This is a separate unit to which the observed characteristics belong, simple (whether it is an employee, an object, a citizen, etc.) or complex (if a team, family or organization is considered).
Sometimes a unit of observation is not a reporting unit. For example, in the case of research conducted inside an economic agent, the reporting unit will be the economic agent, and the reporting unit may be an employee, department, team or product.
Time and place of observation
Setting the observation time requires attention to two aspects:
- time to which the recorded data refers (this may be one “critical moment” or a period of time; in the first case, the phenomenon is recorded statically, in the second case - dynamically).
- data recording time - this is usually a clearly defined time interval; It is desirable that it be as short as possible, so that data recording is carried out as quickly as possible.
For example, during a population and housing census in March 2002, the critical moment was 00:00 on March 18, and the period when the data were recorded was March 18-27. The unit of observation was the household (complex unit).
The place of observation is, as a rule, the place where the phenomenon is recorded, where it is observed and studied.
List of observed characteristics
Determining the characteristics that are being monitored forms a surveillance program in the narrow sense. It requires the establishment of all variables to be registered in order to study the phenomenon of interest in all aspects stipulated by the objectives of the study, while avoiding redundancy of information.
Observed characteristics can manifest in various forms:
- in the form of indicators in statistical reports compiled by economic agents;
- in the form of answers to questions in the questionnaire in the case of specially organized statistical studies.
Correct drafting of the form
In order to obtain all the data necessary for the study and successfully fulfill the goal of observation, the compilation of questionnaires should be performed in such a way as to ensure a logical structure and correctly formulated questions.
The questionnaire should be structured in such a way as to comply with the logical sequence of transitions from one question to another, from one topic to another. If you do not follow the logical structure, the respondent may be disoriented, which, in turn, will affect the answers.
The American Institute of Public Opinion Gallup, which is engaged in statistical research around the world, believes that, when formulating the question in the questionnaire, several basic rules must be observed:
- Make sure the respondent knows the topic of the study. Example: “Do you know about plans to build a business center in area X?”
- Find out the respondent’s overall attitude on the subject. Example: “Do you think this business center is needed in this area?” (Yes / No / Difficult to answer).
- Find answers to questions about specific issues related to the main question. Example: “Do you think the new business center will affect the neighborhood?” (Yes / No).
- Find out the respondents' own points of view. Example: “If you are against the construction of a business center, the main reason will be: a) there are a lot of buildings in this area; b) construction will violate landscape integrity; c) the project will mean the destruction of a park or playground for children; d) another reason. "
In the questionnaire, you can find open questions (where the respondent can give any answer, for example: “What is your profession?”) Or closed questions (where the respondent is given several possible answers, from which he can choose one or several). Questions can also be factual (for example: “What size shoes do you wear?”) Or subjective, aimed at the opinion of the respondent (for example: “What do you think of the government’s intention to increase VAT?”).
Statistical Observation Methods
The main statistical categories in statistics certainly include various methods of statistical observation and research.
There is a wide range of observation methods used together or separately to obtain real, complete and objective statistical information. Methods of observation are one of the basic concepts and categories of statistics. They are classified according to the following criteria:
1. According to the timing of registration of data on various phenomena and processes of observation:
- Current observations, when phenomena and processes are continuously monitored and the data characterizing them, are constantly recorded, for example, in “statistics of civil status” demographic phenomena such as birth, mortality, marriages, and divorces are continuously recorded.
- Periodic observations, when data on phenomena or economic and social processes are recorded at regular intervals, for example, population censuses, agricultural censuses.
- One-time observations, when data related to phenomena or processes are recorded intermittently, sometimes for a special purpose, therefore they are also called “organized” (for example, a public opinion poll on the attitude of citizens towards a new normative act that has entered into force).
2. By the degree of coverage of units of the object of observation:
- Continuous observation, when all units of the statistical population are subject to observation. For example, population and housing censuses.
- Partial observations, when only part of the units of the statistical population is subject to observation.
3. According to how the data are collected, observations are:
- Primary (direct) when data are obtained by collecting, recording directly from statistical units (for example, census, public opinion poll).
- Secondary (indirect) when the data is taken from existing documents (for example, from accounting records).
Statistical census
A census as a statistical observation is a continuous periodic observation method. It has been carried out since ancient times. Even the Romans and Egyptians practiced similar studies.
From a simple number of inhabitants, the census has expanded to other areas of the social and economic life of the population. For example, censuses of housing, livestock, industry, agriculture, trade, etc., began to be conducted.
This is a very time-consuming type of research, requiring large expenses, huge staff, detailed organizational measures and complex processing of recorded information.
A population census is one of the main sources of data in demographic statistics and provides information on the size and structure of a country's population at a particular point in time. It is initiated by the state and regulated by normative acts, however, the responsibility for its organization and implementation lies with the National Institute of Statistics, which also provides processing of the collected data.
The basic principles of statistical research
The census is based on respect for the principles of universality, simultaneity and comparability.
Observance of the principle of universality requires the registration of all persons who fall under the main categories of the population in statistics and are under the jurisdiction of the state. Thus, during the census of the population and housing stock in March 2002, all citizens living in the country were registered regardless of whether they were in the country or staying temporarily abroad, as well as persons of other nationalities or statelessness who were temporarily registered live in the state.
According to the principle of simultaneity, the information collected reflects the existing situation at the same time for all respondents (critical moment), although recording data takes some time. The critical moment is usually chosen in winter, when the observed population is in a state of stability, uniformity, is not subject to fluctuations and random movements (in this sense, holidays or holidays are excluded).
Based on the census, we get volume and static indicators associated with a critical moment. , , .
– , , , , , . , .
, . .
, , , , , . , , .
.
, , , .
. . , :
.
. , , .
. , , ( , , . .).