Grouping and grouping characteristics in statistics are the most important methods for assessing and studying a certain phenomenon that has become the focus of attention of specialists. Grouping helps to identify indicators common to all elements, as well as to determine the structure of the population, to identify the mutual relationships inherent in the elements of the group. After evaluating all the features of the features studied in the project, you can analyze the information received.
Theory and definitions
When forming groupings and applying this method in practice, the basic task is to choose a grouping attribute - it is he who is the basis for the formation of a group of phenomena. The second most important aspect of statistical research is the definition of the interval.
The basis for creating a group is a grouping feature that allows you to determine the homogeneity of a certain group of phenomena, facts. Usually one sign is selected, which is not particularly difficult to identify. You can use quantitative, or you can analyze attributesphenomena to be divided into groups.
No less important than grouping features are intervals. This term refers to the general variety of values inherent in the selected feature, in relation to a particular group. The spacing helps limit the group quantitatively. The width of the interval is defined as the difference between the largest and smallest values of a particular feature chosen by the base to form the group.
Intervals: what are they?
As a rule, students studying statistics, mathematical statistical research, as well as similar disciplines, more than once have to deal with tasks formulated as follows: “Please indicate a grouping feature for the next sample, estimate the size of the interval by defining it belonging to a particular type. There are four types of intervals in total. If the width of this indicator for different groups participating in the study is the same, the intervals are called equal. With a discrepancy in this phenomenon, one speaks of unequal intervals. These can change arbitrarily or naturally. The former are considered free.
Having determined the grouping characteristics, it is possible to evaluate the interval for sampling as open or closed. The first term involves the refinement of one boundary of the interval - the minimum or maximum quantitative value of the attribute. The case is called closed when both boundaries are present.
Attention to aspects
Determining the main grouping features for a specific sample, it is importanttake into account the circumstances surrounding the phenomenon under study, their variability. The formation of a group obliges to follow the principle of observing the time scale, the conditions describing the place, the conditions of action. The formation of a grouping begins with the identification of a feature for combining facts. You can choose such a sign, on the basis of which the population can be divided into a group. This parameter is the base of the grouping.
You can use quantitative, attributive grouping features. The first group can be described by numbers - this will be the age of the individuals involved in the study, or the prices, the volume of transactions. Qualitative indicators describe the state of each of the objects included in the grouping. So, if we are talking about sociological work, attributive features can be called the gender and nationality of the people who took part in the study.
Features and groups
Grouping features in the construction of an analytical grouping are effective, factorial. All signs can be combined according to belonging to one of these two types. Factorial - those whose influence corrects other signs.
Grouping features are the basis for the formation of groups. The number of such is determined by the features of the planned work, as well as the nuances of the characteristics on the basis of which the sample as a whole is formulated. Much depends on the level of variability of the trait and the number of objects included in the study.
Forming groups, taking into account the qualitative parameters,it is necessary to allocate such a number of varieties that coincides with the states of the trait. For example, if we are talking about gender, then in the general case there will be two classes. Using quantitative features as a basis for grouping, it will be necessary to estimate the number of items, the level of variability of the feature. The stronger the trait is prone to change, the higher the variability, the more classes will have to be distinguished.
Features of choosing intervals
After evaluating the grouping characteristics and forming a grouping, it is necessary to determine the interval inherent in it. If it is unequal, is it reasonable to estimate? whether it is prone to progressive increase, decrease. There may be specialized intervals. In the case when the trait is variable within rather narrow limits, and the distribution is relatively uniform, it is necessary to form groups with equal intervals. To estimate the range of variation, you will have to analyze the population for the presence of anomalous points, exclude them from the total sample.
If the interval is open, its width is equal to the width of the nearest closed one.
Examples and phenomena
Grouping features when constructing an analytical grouping become the basis for determining the classification, if they belong to the qualitative ones. So, if we determine the form of ownership for each subject of our country, and then divide all the studied objects into groups, this will be a classification taking into account qualitative parameters. In the documentation, in accordance with the rulesfixing information, it is necessary to alternate information about the features underlying the grouping and reference data. This format was adopted several decades ago, since then the design rules have been broadly preserved.
When formulating the accompanying documentation for the study, you will have to indicate in it which grouping features the objects selected for work belong to: quantitative, qualitative. Normally, they are sorted, taking into account the level of detail. For each selected category, the indicators of the attribute on the basis of which it is compiled must be recorded. When choosing a quantitative parameter, which has a small variety of values, it is possible to divide the phenomena by calculating the units that are inherent in a particular indicator.
Individuality of the situation
Grouping and grouping feature for a particular study are selected specifically, taking into account the characteristics of the work. For example, as factors, you can take object numbers, dates of documentation, personnel identification numbers of persons, and other similar features. To avoid confusion, the signs must be recorded in the explanatory note to the ongoing statistical study. It is common practice to form instructions, following which a specialist completes research documents.
Grouping and grouping feature have become important elements of classification, sorting of information used to draw up transportation plans, determine economic and other mutual relations between objects. On the basis of thisthe statistical approach forms the tariff policy. At the same time, one should not forget about the possibilities of feature specialization. Such work involves the correction of parameters, taking into account the peculiarities of the conditions: in different situations, the same types of indicators may appear.
Groups and their characteristics
According to the number of grouping features, we can talk about combined groups and simple ones. The first option assumes the presence of several signs at once, in the second case only one is used. A sign is selected after analyzing the nature of the object being evaluated, the phenomenon. The theoretical, economic analysis of all aspects of the object, the specifics of its development are aimed at choosing the most significant phenomenon as a basis for dividing into classes.
If attributive grouping features are selected when forming a category, their diversity is quite large, it is necessary to combine some similar ones into groups. Attribute classification is used only in the case of a relatively small variety of objects to be sorted. To justify the belonging of an object to a particular group, it is reasonable to first work out a classification that describes the sorting rules. The distribution of signs is carried out with a preliminary selection of all parameters, taking into account the tasks to be solved by the specialist. The grouping, in turn, is formed for one specific, relatively small job.
Summary and statistics
Investigation of some objectin statistics begins with the observation of its development. The next stage is the compilation of a summary intended for the formation of an information code, ordering information, and systematizing data. Already on the basis of this, it is possible to characterize and evaluate all the features of the population that attracted the attention of the researcher. A summary consists of several related operations for analyzing the data obtained during observation in order to determine the patterns of the phenomenon. Organized scientific processing of observational materials involves identifying the results for groups and the sample as a whole, ordering the information and arranging them in a tabular form.
You can make simple summaries, sometimes you can not do without complex ones. In the first case, the overall result is calculated for the object under study, the second option involves grouping individual units, calculating the results for each category and the entire phenomenon as a whole, and then compiling tables with the data obtained. Decentralized reports are compiled if there is some leader, while the direct collection and processing of data is the responsibility of specific places. If information is collected, processed at one point, the process is controlled from here, they speak of a centralized summary. These are indispensable when conducting several studies at the same time.
Step by step
Before compiling a statistical summary, it is necessary to form an observational program, select grouping features and think over a system for evaluating the data obtained during the follow-up. Summary starts withselection of a sign for classification, after which they proceed to the choice of the order of compiling categories. They develop statistical indicators that would help describe individual classes and the entire sample in general, make table layouts, into which they then enter the results of the research.
In most cases, a simple summary is not enough, since only general conclusions can be drawn from it. To clarify the data, it is worth choosing qualitative, quantitative grouping characteristics, forming groups on their basis and studying all the data obtained by dividing the population into interconnected subsections. Grouping is the most convenient basis for information analysis. Then, based on the generalizing parameters, all the collected data are analyzed.
Grouping: statistics features
Choose qualitative, quantitative grouping characteristics, on their basis, make up categories that allow you to break the entire population into several related subtypes, taking into account some important phenomenon. Categorization allows you to form homogeneous classes. Such work simplifies the definition of mutual relations, structural elements. Grouping is the best way to find out to what extent individual units influence the final result.
It is quite common to group work data to assess the productivity of individual sections. Based on the analysis of the data, it is possible to determine how large the opportunities for productivity growth with a change of staff are. In addition, they identify the difference between frontline workers and other personnel and evaluateopportunities that will open up for the company if all workers are of the same high level.
Features and types
When conducting economic analysis, most often grouping is carried out according to factors determined by labor resources, objects and means of labor. Each of these aspects greatly affects the volume of products produced by the enterprise.
When choosing a grouping feature, it is worth remembering the purpose of the study, the characteristics of the sample and the results of the preliminary analysis. A phenomenon studied by specialists can be very complex, massive, and characterized by a branched structure, but the reverse situation of relative simplicity is also possible. Assessing these features, as well as the tasks assigned to the analyzes, objects are grouped taking into account one, two, and a large number of features, thereby forming combinational groupings. Analysis of the objectives of the study allows us to speak about its belonging to the typological, analytical, aimed at determining the structure.
Typological grouping involves the distribution of the studied phenomena into homogeneous subgroups. Structural is practiced if it is necessary to divide a homogeneous group into several, while to describe the structure they resort to some feature that changes for individual representatives. So, it is of this type that the population sample will be grouped according to the level of profit received. Statistical information, being analyzed for several periods, allows us to evaluate the structural changes in the sample, shifts. Finally, factorial is such a grouping, on the basis of whichdetermine the interconnections of different phenomena, features that are in the focus of attention of researchers.
Putting theory into practice
Usually, economic analysis requires categorization based on structure or analytics. Structural classes are necessary to evaluate the structure, composition of the sample and deeply analyze all the data available to analysts. Experts evaluate how much phenomena change within the totality of phenomena, while identifying links with certain features.
Analytical grouping is indispensable if you need to evaluate the relationship of objects, indicators that describe the sample. Indicators can be effective, others are defined as generalizing, some manifest themselves as factors influencing the results.
Selection of features for groups
When choosing the basis for the study, it is important to approach the issue responsibly, since the correct identification of signs largely determines the success of the entire event. It is important to use only significant, typical indicators that correspond to the goals set for the analysts. Correct will be a statistical analysis, which takes into account the features of time and place. If in a certain case a number of signs are appropriate, for another situation it may be unacceptable. When studying a complex phenomenon, you should select several features, and group them taking into account all of them.
The basic rule of statistics is the correct translation of a phenomenon into a numerical valueexpression. When choosing quantitative traits as a basis for grouping, it must be remembered that the number of classes is determined by the number of objects under study, the variability of the trait chosen as the base, the tasks of the work, and the specifics of the phenomenon that is in the center of attention. Sometimes the number of groups is chosen based on previous work.
Nuances of wording
Having chosen grouping characteristics and having studied the information obtained during observations, taking into account the division of phenomena into categories, it is necessary to compile a statistical table. It is the tabular format that is considered the most visual, effectively reflecting the results of the work carried out. The table is quick and easy to read, easy to understand, briefly and concisely demonstrates a large amount of information, makes it easy to compare parameters and identify their dependencies.
Currently, there are several general requirements for all statistical tables compiled as a result of grouping characteristics. It is important to create concise tables with detailed titles that reflect the scope of the questions considered, the sample boundaries, the time period of the study, and the units of measurement used by the researchers. If different units are used for different columns and rows, you will have to sign them in the corresponding cells for ease of reading the material.
It is wise to supplement the tables with notes to indicate where and how the information was obtained. They can describe in detail the essence of the selected indicator and explain the displayed information in a different way. If some data is a totalcalculations, this should also be mentioned in the note to the table.
When preparing a summary, modern analysts resort to generally accepted conventional symbols. For example, if there is no phenomenon, a dash is put in the cell corresponding to it - the dash symbol. In the absence of meaningful information, they put an end to it, and dots indicate the absence of specific information. An alternative to the ellipsis is the phrase "No information." The use of these common symbols makes the table easier to read.
