Sampling method. Key Questions for Sample Surveys

Marketing research is a very expensive undertaking and is not always within the means of enterprises. In this case, they turn to specialized organizations engaged in performing this type of work. Large companies often collect information themselves and employ special staff.

Depending on the nature of the use of information, methods of obtaining it, research techniques and its final results, different kinds and methods of conducting marketing research. The choice of a particular method should be determined, on the one hand, by the required accuracy and reliability of the results, and on the other, by the costs of its implementation.

Desk research are carried out on the basis of official printed sources of information and provide a general idea of ​​the state of general economic conditions and development trends of individual markets. In this case, methods are used economic analysis combined with elements of econometrics and mathematical statistics.

Observation Typically used in search engine marketing research. It allows you to maintain stable observation conditions and use technical means. Observation can be hidden (using television cameras, for example) and open (with the direct participation of the researcher). Depending on the goals pursued, observation can be free and standardized (certain criteria for the study are set).

Experiment As a method of marketing research, it is assumed that the analysis should exclude the influence of all factors except the one being studied. Therefore, the experiment assumes the presence of at least two comparable study groups, one of which is experimental and the other control. For example, this could be two products or two consumer groups.

Experiments taking place in an artificial setting (for example, tests of products, prices, advertising) are called laboratory, and those carried out in real conditions - in the field. The first ones allow you to control extraneous factors, the second ones do not exclude the influence of extraneous factors.

Field research, although the most complex and expensive, is also the most effective method market research. It is used only by large companies. It allows you to quickly and comprehensively become familiar with market requirements, trade practices, sales methods, prices and many other conditions. It is also important to be able to establish personal contacts with potential buyers, purchase samples of goods that are in greatest demand in a given market, etc.

This method allows you to obtain and process primary information, which, although more expensive, does not provide a real picture of market demand and customer requirements for the company's products and take these results into account when developing market tactics, including pricing policy and sales organization issues.

Test sales method used in the absence necessary information about the market and time for its comprehensive study, as well as when introducing new and rare goods for the market being studied. Despite a certain risk of incurring losses, it provides an opportunity to establish direct business relationships with possible buyers.

The market in which the test is taken must be representative of the target market in terms of: population structure and its needs, characteristics of trading enterprises, state of competition, influence of funds mass media. It should be long enough to accommodate repeat purchases, and optimal option until they stabilize, which will allow us to predict market share.

However, the trial sales method is associated with high costs, difficulties in selecting suitable markets, determining the duration of the study, reducing the effect of surprise for competitors, and additional workload for sales staff.

Personal business contacts with representatives of other firms is important for studying markets. These contacts are established and maintained through mutual visits to companies, during meetings business people at fairs, exhibitions, auctions, presentations, commodity exchanges, etc.

Personal contacts between company representatives and the buyer have great importance when studying the market for technically complex products, such as machinery and equipment. In this case, the seller’s representative simultaneously acts as a technical consultant to the buyer. Such contacts can become a source of proposals for improving products and increasing their competitiveness.

Simulation modeling represents a mathematical, graphical or other model of controlled and uncontrollable factors that determine the strategy and tactics of the company and in subsequent experiments on the model in order to study the impact of changes in these factors on the object of study. Simulation modeling makes it possible to comprehensively study the many factors that determine marketing strategy.

Modeling is most widely used to study consumer behavior. The most well-known models of consumer behavior are probabilistic (stochastic), linear-experimental, and information processing models.

Probabilistic models are based on the assumption that previous, and especially recent, purchases determine future consumer behavior in the market. These models are used to predict demand for new products, to determine loyalty to product brands;

Linear experimental models are usually descriptive in nature and are used to model potential demand for goods, identify trends in consumer behavior in relation to specific goods, etc., such as the share of a particular brand in the total volume of consumer demand.

Models of information processing are based on the premise of multiple sources of information for the consumer to make a decision on the choice and purchase of a particular product.

Survey represents an oral or written appeal to certain respondents with questions containing the research problem.

This is the most common data collection method in marketing. It is used in about 90% of studies. The classification of surveys is shown in Fig. 1.

Rice. 1. Classification of surveys

The source of information when conducting mass surveys is the population that is not related by the nature of its activity to the subject of analysis. In specialized surveys, it is specialists (experts) - persons whose professional activity closely related to the subject of research, they are the main sources of information. Therefore, specialized surveys are often called expert surveys. They are used either at the beginning of market research to identify a problem, or at the final stage when a decision needs to be made.

One-time surveys show only the current reaction of market participants to the activities of the enterprise and its products, while repeated surveys allow us to identify life cycle goods, consumer demands and purchasing preferences.

Complete surveys are usually used when studying the opinions of users of industrial goods, since their circle is relatively limited. In the consumer market, the number of potential buyers is so large that it makes it virtually impossible to use this method. In such cases, sample surveys are conducted on a sample of the population, which fairly fully reflects the properties of the general population. Such a sample is called representative.

The main survey forms are questionnaires and interviews. In the first case, the interviewee himself answers the questions in writing; in the second, during personal communication with the interviewee, the interviewer asks questions and records the answers.

Personal interview- a universal method of conducting a survey. The interviewer can not only ask more questions than provided by the questionnaire, but also supplement the interviewee’s answers with his own personal observations. This is the most expensive way to obtain information, both in terms of money and time spent. It requires the training of a qualified staff of interviewers.

It is somewhat cheaper and faster to collect information during a telephone interview. And in this case, the interviewer can clarify questions that are not entirely clear to the interviewee. However, the potential circle of respondents is limited to phone owners, firstly; the issues being addressed cannot be too personal; third, the interview should be relatively short.

Personal interviews can be individual or group (for example, conducted simultaneously with members of the same family, neighbors, team members, etc.).

In the practice of conducting marketing research, postal surveys, especially panel surveys, have become widespread. They provide information on a wide range of issues from large groups of consumers by repeatedly surveying them at regular intervals. Panel surveys make it possible to keep a constant record of ongoing changes in external environment, receiving information about the quantity of goods purchased by the family; financial expenses; preferred prices, types of packaging; differences in the behavior of consumers of different social groups and regions; brand loyalty, etc.

A consumer panel, as a research method, along with significant costs, is also associated with the problem of ensuring representativeness. The problem is not only in choosing objects and obtaining consent to cooperate, but also lies in the possible refusal of participants to cooperate, in their changing their place of residence, in moving to another consumer category, in a conscious or unconscious change in behavior (consumers begin to “prepare” for purchases, the share of spontaneous purchases decreases), in negligence in responses during long-term cooperation; in physical death, finally.

The accuracy of the results of a survey conducted in any form largely depends on the instrument used - a questionnaire or an interview form.

Questionnaire (questionnaire) is a system of questions aimed at identifying the characteristics of an object or subject of research.

It can be divided into four parts:

• introductory, where a respectful attitude towards the respondents is expressed and it is indicated who is conducting the survey; for what purpose; instructions for filling out the questionnaire.
• contact, where the questions are located that aim to interest the respondent and introduce them to the range of problems being studied;
• control- with questions to ensure the reliability of the data (for example, if in the contact part the main question was: “Are you familiar with the basic methods of caring for the skin of the eyelids?”), then the control part could be of the following type: “What are the methods of caring for the skin of the eyelids?” Do you think the most important?").
• final- with questions that take away from respondents psychological stress, allowing us to identify their socio-demographic characteristics (gender, age, place of residence, social status, education, income level, etc.), and end with words of gratitude to the respondent for participating in the survey.

Particular attention should be paid to ensuring that the main and control questions do not follow each other, since most people answer next question, being impressed by the content and response to the previous one. The most difficult questions that require thought should be located in the middle of the questionnaire.

The questions themselves should be simple, understandable, unambiguous and neutral, and they should move from simple to complex, from general to special, from neutral to subtle (delicate).

The time required to fill out the questionnaire during a postal survey should not exceed 20 - 30 minutes.

The questions included in the questionnaires are open and closed. Open questions give you the right to formulate answers yourself. Table. 3.3. This circumstance, although it makes processing the survey results more difficult, in some cases can offer an unexpected solution to the problem being studied and thus compensate for the costs.

Table 1

Kinds open questions

Name	The essence of the technique	Examples
Unstructured question	Allows any answer wording	What do you think about Sony?
Selection of word associations	The respondent calls individual words, associated with the words that the interviewer calls	What associations do you have when you hear the word “Sony”? or “Rest”?
Completing a Sentence	Complete an unfinished sentence	I buy Sony products because...
Completing the story	Finish an unfinished story	You visited a Sony store and were overwhelmed by thoughts and feelings.
Completing the drawing	Imagine yourself in the place of one of the two heroes usually depicted in funny drawings, and on his behalf express your opinion	The picture shows two participants in a dialogue. One of them says: “The Sony store always has a wide selection. What can you say in response?
Thematic apperception nal test (perception test)	Make up a story based on the picture	For example, two customers are depicted at the counter of a Sony store. What is happening or could happen?

Closed questions offer the respondent a set of possible answers to the question. The classification of types and examples of asking closed questions are given in Table. 2

One of the tasks that a researcher faces when conducting research is collecting the necessary empirical data about the object of study. The set of elements that make up the object of study is called the general population (GS). The simplest, at first glance, method of collecting data is a continuous survey of the HS. However, the use of a continuous survey is not always possible. In this case, a sample survey is used. The essence of the sampling method is that only a part of the elements of the HS is examined, which is called the sample population (SV). The inventor of the sampling method was life itself. Indeed, even before the theoretical justification of the possibilities of using the sampling method, statisticians were forced to conduct sample surveys. The main reasons for this were lack of time and funds.

The sampling method allows not only to reduce time and material costs for conducting research, but also to increase the reliability of research results. This statement may cause confusion: how can more reliable data be obtained by examining a smaller part of the HS? However, practice shows that the reliability of the information obtained when using the sampling method can be not only no lower than with a continuous survey, but even higher due to the possibility of attracting higher-class personnel and the use of various procedures for controlling the quality of the information received.

In addition, the sampling method has a wider scope of application. The breadth of the scope of application of the sampling method is explained by the fact that the small (compared to GS) sample size allows the use of more complex survey methods, including the use of various technical means(for example, video and audio equipment, personal computers and the Internet, as well as complex measuring equipment).

Sample surveys are widely used in the work of state statistics bodies. Most often, large and medium-sized enterprises are covered entirely; observation, and observation of the activities of small enterprises is carried out using sample surveys. In some cases, sample observations are used in combination with complete censuses and records. For example, the program of the All-Russian Population Census of 2002. contains both questions of continuous observation relating to the entire population, and questions of sample observation of 25% of the population to characterize the main occupation, position, place of work, as well as questions of a 5% sample survey to study marriage and birth rates.

Question 56. Marketing program, its main sections and stages of development

The firm's specific purpose or program is usually clear from the outset. However, over time, as the organization grows and enters new products and markets, the program may lose its clarity. Perhaps the program will remain clear, but some of the management will no longer be interested. Or maybe, while maintaining clarity, it will no longer correspond to the new environmental conditions.

It's time to ask yourself:<Что представляет собой наше предприятие? Кто наши клиенты? Что ценно для этих клиентов? Каким будет наше предприятие? Каким оно должно быть?>

Many firms develop formal mission statements in response to these questions. in writing. A well-developed mission statement allows the company's employees to feel like participants in a common cause in the development of emerging opportunities, gives them a purpose, emphasizes their importance, and aims for achievements.

The mission statement must clearly indicate the scope (or scopes) of the firm's activities. The boundaries of areas of activity can be defined by products, technologies, customer groups, their needs, or a combination of several factors. A market-oriented mission statement defines an enterprise in terms of its service activities specific groups consumers and/or meeting specific needs and requests.

In the process of strategic marketing planning, short-term (annual) and long-term marketing programs for enterprises are developed. A marketing program is a set of interrelated activities that determine the actions of an enterprise for a given period of time across all elements of marketing. Short-term marketing programs are distinguished by great detail and specificity in programming the actions of the enterprise. Long-term - cover activities designed for a long period of time according to the adopted marketing strategy. A unified marketing program is an interconnected system of programs for individual markets and groups of homogeneous products. It serves as the basis for developing plans for research and development, production, sales, service, etc.

When preparing a marketing program, it is necessary to take into account that an enterprise’s entry into the market (in addition to resource and material and technical support) presupposes:

in-depth analysis of the market situation and forecast of its development;

a certain degree of freedom in establishing economic ties;

own position in the market, taking into account the commercial risk associated with competition;

technological and organizational policies that allow influencing market conditions;

collection, processing and analysis of information about competitors that determine the market situation;

the presence of highly qualified specialists and managers capable of practically implementing marketing decisions.

Marketing programs are developed on the basis of comprehensive market research, identifying customer requests, marketing strategies and tactics. They are the basis that ensures the interaction of the enterprise’s commercial and sales services with scientific, technical, design and production departments.

When conducting research on the modern labor market, in addition to analyzing statistical indicators, they most often use following methods collecting information:

Questionnaire;

Interview;

Observation;

Document analysis;

Sociometric survey;

Testing;

Experiment, etc. .

The effectiveness of a questionnaire survey is determined by the quality of the developed questionnaires and the principles for selecting respondents. Basic rules to ensure the quality of a questionnaire survey: it is necessary to record only the most significant questions, the answers to which cannot be obtained using official documents; the wording of the questions must be clear to the respondent and unambiguous, adequate to the respondent’s level of knowledge, for which each question is pre-tested; it is necessary to take into account the factor of memory and antiquity of the event in the labor market; the question should be raised positive reaction the respondent and the desire to provide reliable information, while it is necessary to formulate questions quite correctly and sensitively, respecting the respondent,

Questionnaire questions According to their structure, they are divided into open, closed and semi-closed. Open questions - require the respondent to independently formulate an answer, for example: “What do you think about the decision of the head of the department?” The disadvantage of open questions is the vagueness of the answers and the complexity of processing, as well as the high probability of subjective interpretation, which accordingly leads to incomparability of results. Closed questions contain list of possible answers. of this type questions is that, due to objective reasons, the researcher cannot foresee everything in advance possible options answers. Semi-closed question - after the proposed list of alternative answers, the respondent is given the opportunity to express his personal opinion regarding certain provisions of the labor market.

The form of questions can be direct or indirect. Direct questions relate directly to the current situation, for example: “Are you satisfied with your job, boss, colleagues, etc.?” The disadvantage of direct questions is the reluctance of people to give objective information on them. Indirect questions are formulated as follows: “Suppose (or if) you moved to a new place of work, would you like to continue working with former boss, colleagues, etc.?"

By function, questions are divided into basic, filtering, control and contact. Basic questions are designed to obtain information about the situation on the labor market. Filtering questions are used to exclude incompetent respondents and check their level of awareness of the situation on the labor market. Security questions are used to clarify the veracity of the answers. Contact questions are necessary to adapt the respondent to the questionnaire and establish contact with him.

The questionnaire should begin with a contact question, it should be easy to understand and make the respondent want to answer further questions and provide sincere information.

The structure of the questionnaire includes introductory, main and demographic parts. The introductory part contains an appeal to the respondent, which must indicate which organization is conducting the survey, the purpose of this survey and how the results of the labor market research will be used; the importance and significance of the respondent’s personal participation in the survey is emphasized, the anonymity of responses is guaranteed, and the rules for filling out the questionnaire are outlined. The main part of the questionnaire usually includes several blocks of questions. The first block is aimed at obtaining factual information and does not contain much difficult questions. In the second block the question becomes more complicated. For example, it turns out value orientations, social attitudes, opinions and assessments of respondents. The third block contains the most personal and Control questions, the purpose of which is to deepen and clarify information. The demographic part of the questionnaire contains questions regarding social status respondent and his socio-demographic characteristics: position, profession, Family status, gender, age, work experience, income per family member, etc. .

An interview is a method of obtaining information through a direct, focused conversation between an interviewer and a respondent. The main areas of application of the interview method: to clarify the problem and formulate hypotheses on the labor market; to develop a methodology for large-scale surveys; as the main means of collecting information about social and labor relations in small sampling; as an additional method of collecting information about the labor market; in control studies to clarify and verify the information array.

Based on the technique or form, a distinction is made between formalized (standardized) interviews, when the wording of the questions, their order, number and list of possible alternative answers and the form of recording are assumed in advance, and informal or non-standardized interviews - questions and expected answers are not determined in advance, the recording is standardized . An informal interview is the most flexible, dynamic type of interview in a natural situation, indispensable at the exploratory stage of labor market research, when it is necessary to expand knowledge about the object and compile a questionnaire. The disadvantage of an informal interview is the laboriousness of processing and analyzing materials, as well as the typical dependence on the level of professional qualifications of the Interviewer and the possible subjectivity of His judgments, that is, an arbitrary interpretation of understanding and the labor market.

According to the procedure, personal and group interviews are distinguished. Personal interview is a common method of studying any problem on the labor market, which involves conducting interviews directly at work, on the street, in houses or some crowded place by specially trained interviewers. This method is called "face-to-face" and involves actual interaction between the interviewer and the respondent. A group interview involves simultaneous interviewing of a small number of people - a group, family, team, usually in the form of a discussion.

For a group interview, a group (up to 10 people) is selected, a certain topic is discussed with it, the course of the discussion is directed by the moderator, that is, a specially trained interviewer. The designated employee must create a relaxed atmosphere.

Group discussions are characterized by the following tendency: restraint of statements, it turns out at the beginning, gradually disappears, and participants more actively begin to express their attitude to the subject of discussion and the motives for their actions, which they would never do in a more formal atmosphere. In addition, there is a dynamic of group interaction, which is expressed in the fact that when one of the participants expresses his opinion, others vigorously discuss it, and this gives rise to many ideas in the system of correct labor market research. An in-depth (clinical) interview is aimed at obtaining the most complete information o social and labor relations, needs, motives of the respondent. The main idea of ​​an in-depth interview is to activate the main idea and analyze associations. The most distant associations reveal the motives of behavior. The interviewer's role is limited to demonstrating empathy and encouraging expression. Individual in-depth interviews are especially effective when discussing deeply personal, intimate issues that are usually not discussed in groups, although they have an impact on the formation of social and labor relations in the labor market.

Telephone interviews are characterized by cost-effectiveness, minimal risk (in particular, of a criminal nature) and efficiency of labor market research. At the same time, when conducting a telephone survey, the questionnaire should be as short as possible, the questions should be easy to understand, and the use of illustrative materials is impossible.

The postal interview questionnaire is sent by mail along with a cover letter and a stamped, self-addressed envelope. The advantages of this method are its relative cost-effectiveness; it is designed for respondents who are geographically dispersed. The main disadvantages of this method are the lack of interaction between the interviewer and respondents, which does not allow questions to be clarified and explanations given, as well as the low percentage of responses received (no more than 30%).

The observation method provides for targeted and systematic recording of processes in accordance with the objectives of the study; it is used at the stage of drawing up a program, when it is necessary to obtain preliminary data about the object, clarify the problem, and formulate a hypothesis. This method can also be used to verify data obtained by other methods.

Distinguish the following types observations on the labor market: direct and indirect; included and not included; structured and unstructured. Direct (direct) observation involves recording various social and labor processes at the moment of their occurrence, and indirect observation - certain social and labor processes have passed. Participant observation presupposes the presence of a researcher in the situation under study, which he can both influence and be influenced by. With non-participant observation, the researcher is away from the observed and does not directly participate in it.

When conducting structured observation, the researcher determines in advance what he will observe and record in a special standard observation chart. Unstructured observation involves this type of observation; the researcher does not determine in advance which elements of the phenomenon or process being studied he will observe. This type is often used at the exploratory stage of labor market research.

Depending on the nature of the environment, observation can be field (if the study of social and labor processes occurring in a natural environment - at an enterprise) or laboratory, that is, carried out in an artificially created situation.

The method of document analysis is based on specially created material media of information intended for its recording, transmission and storage. Solving a research problem requires determining which documents need to be studied so that the data about the object is objective and reliable.

According to the form in which information about the labor market is recorded, documents are divided into: written (printed, typewritten, handwritten) iconographic (film, video and photographic documents) phonetic (tape recordings). Depending on their status, documents are classified into official (government materials, regulations, statistical reporting data, documents of various organizations, archives, etc.), unofficial documents (personal cards, questionnaires, statements, etc.). According to the sources of information, documents are divided into primary, compiled on the basis of direct observation or survey, and secondary, which is a processing, generalization made on the basis of data from primary sources.

The disadvantages of the method are the lack of description of the social atmosphere in which opinions were expressed and assessments were made, which makes it difficult to adequately interpret events and does not make it possible to understand the motives for making decisions; the need to analyze the intentions of the document compilers, to identify whether the general environment in which the document was created contributed to the objective recording of information or vice versa.

The test is a short standardized examination, the purpose of which is to demonstrate the presence and degree of expression of personality traits, abilities and skills, motives and mental states. Tests do not allow us to draw a clear conclusion, but they provide useful information when installed correctly.

The importance of testing as a method for studying social and labor relations in the labor market is determined by the following: a person often cannot give objective information about himself, since most people simply do not think about their character, personality and are not able to assess the presence and degree of expression of certain traits character; true motives one’s own actions and behavior are not always realized or are perceived biasedly; a person does not always want to present truthful information that corresponds to what he knows (or thinks) about himself, that he knows, since all people tend to present themselves to others in the most favorable light, therefore sometimes a special scale of “lies” is “built into” tests , which allows you to assess how much a person strives to decorate himself; a person may have special reasons to give biased information about himself, so information about them can only be obtained by indirect methods psychological testing, asking the question correctly.

Testing is used in research: career guidance of youth, abilities and leadership in different areas of activity, advantages of candidates for workplace etc. A new aspect of modern employment in Ukraine has become testing of job applicants. At the same time, this trend should have legal basis. Yes, in legislation European countries provisions on the concept of testing, a list of types of tests, acceptable limits for the selection and use of certain tests, protection of personal data of citizens who are hired are clearly established.

Among the most complex methods collecting information about the labor market includes an experiment that allows you to obtain unique information, which is almost impossible to obtain by other methods. The effectiveness of an experiment in the labor market system depends on taking into account the conditions: when creating an experimental situation, characteristics that are important from the point of view of the problem under study are selected as control ones; one should take into account those changes in the control characteristics of the experimental group that are introduced or changed by the researcher himself; the experimental process should not be influenced by those phenomena that do not relate to the experimental situation, but are potentially capable of changing its state at a specific point in time.

There is no national market data bank in Russia yet, so the necessary information has to be collected “bit by bit,” creating a more or less objective picture.

There are two methods for collecting such information - continuous observation, when all units are examined population, and selectively, in which information is obtained only from a portion of the units of this population. More common in marketing research is the selective method of collecting information, which has the following advantages:

1 – information can be obtained much faster, which ensures timeliness of information;

2 – data obtained selectively is much more complete, because it is possible to characterize each unit of observation much more fully;

3 – information is more complete, because less number information collected, which means less possible errors.

However, the advantages of the sampling method can only be realized if, when organizing and conducting sample observation strictly follow certain rules. These primarily include ensuring the quantitative and qualitative representativeness of the sample.

Quantitative representativeness means ensuring in the sample such a number of units that one can reasonably judge the magnitude of the characteristics being studied.

If nothing is known about the general population, then the required sample size is calculated using the formula:

where n is the required sample size;

D p is the sampling error we allow for the share (specified accuracy);

t – coefficient depending on the probability with which the specified sampling accuracy is guaranteed;

p, q – shares opposing events(p + q = 1).

If nothing is known about the population, then take

p = 0.5 and q = 0.5, and the sample size calculated for these values ​​will be sufficient for any other "p" and "q" ratios.

In marketing research, a probability of an event equal to 0.954 is usually considered quite acceptable, at which t = 2 (from the table with p = 0.997, t = 3, etc.).

Example . Traders who sell agricultural machinery need to know how many farms use mowers. It is hardly possible to survey all households, so it is better to conduct a sample survey. But how many farms should we survey?

For the example in question:

p – share of farms using haymowers;

q – proportion of farms that do not use mowing machines;

If we can tolerate a sampling error of ±5% then D p = 0.05 and thus have a sample size

farms.

If something is known about the population (for example, from past studies it is known that there were 800 farms in the area of ​​which 80% used mowers), then the sample size is calculated using the formula:

,

Where N – volume of the general population.

For this example

farms.

If it is necessary to determine average value population (for example, the average service life of an electric mower), then the sample size is calculated using the formula:

,

where s 2 – dispersion characterizing variations of the studied trait;

D x – maximum permissible sampling error for the average.

For example, past research shows thats 2 amounts to±2.25 of the year. Then, with acceptable accuracy, we have±0.3 of the year.

farms.

The sample must be representative (Figure 1.4), i.e. should be represented by the maximum possible number of groups in the population.

Figure 1.4 - Qualitatively representative sample

Figure 1.5 - Qualitatively non-representative sample

To avoid unrepresentativeness (Figure 1.5), random mechanical selection is used in market research. Its essence is that random objects are examined at a certain interval.

After calculating the sample results, the effectiveness is assessed by calculating the actual error

a) for average b) for share

; .

Example. As a result of a sample survey of farms, it was found that47 % some of them use haymowers. A total of 194 farms were surveyed.

.

Hence, confidence interval for farms purchasing mowing machines it ranges from 0.47-0.06 to 0.47+0.06 i.e. from 41% to 53%.

Based on this data, you can build your commercial policy.

The most common method of collecting market information is the questionnaire method.

The selective method of collecting information is a method in which a part of the whole is selected, and the characteristics obtained regarding this part are applied to the entire population.

The unit of observation is the direct, primary source of information, which can be an individual buyer, family, enterprise, social groups etc. The unit of observation is determined depending on the goals and objectives of the study.

The entire set of observation units that has the properties of interest to the researcher is called the general population.

A sample population, or sample, is a portion of the population that is selected for research and analysis.

The main goal of any sample study is to ensure that, as a result of the study, sample population get statistical characteristics, which fairly well reflect the properties of the general population. If a sample reflects the properties of the population quite well, it is called representative.

During selective observation, data recording errors may occur. These errors are not unique to the sampling method. They also arise during continuous accounting. However, when sample study Errors arise that are not inherent in continuous observation - errors of representativeness.

Errors of representativeness are the discrepancies between the general indicators of the sample and the general population in the conditions of correctly conducted primary data registration. Representativeness errors can be systematic or random.

Systematic errors of representativeness arise due to violation of the requirements of sampling theory. In particular, such errors arise due to a violation of the sample structure, when the sample is formed from observation units with some values ​​of the characteristics being studied to the detriment of observation units with other values ​​of the characteristics. Sampling error is also called sampling bias. For example, if only large stores are selected from the entire population of trading enterprises to study the structure of sales of goods, then such a sample will not reflect the complete sales structure characteristic of the entire retail network.

In research practice, in order to eliminate sample bias, it is formed in two ways.

The first way is to build a miniature model of the general population through conscious selection. For example, if a sample is formed from residents of a certain settlement(district), then a part is taken that has a structure identical to the structure of the entire population (based on the main characteristics - gender, age, occupation, etc.). This type of sampling is called quota sampling.

The second method is to form a random sample. Random selection is not a random selection, but a specifically organized selection, in which each unit has an equal chance of being included in the sample.

Both of these methods are most often used not independently, but in combination with each other. The design and specific methods of selection are determined by the characteristics of the observation units and the objectives of the study.

In theory, random selection has significant advantages. However, it is not always possible to practically apply it for marketing research. For random selection, you need to have a sampling frame, i.e. full list units of observation. Obtaining such lists in some cases is difficult or even impossible. For example, if it is necessary to identify the degree to which families are provided with technically complex goods, there must be a list of all families in the area under study (city, region, etc.). Compiling such lists is a difficult task. Therefore, the selection of the sample is carried out through multi-stage selection. Sampling methods will be discussed in more detail below.

At correct formation samples systematic errors there will be no representativeness. However, in this case, the characteristics of the sample and the general population will not necessarily coincide.

The discrepancy between the indicators of the sample and the general population under conditions of correct selection and accurate registration is called random errors of representativeness or sampling errors. Random errors are due to the nature of the sampling method, i.e. they are a consequence of the sample size being smaller than the population size.

When conducting marketing research, there is a need to obtain information about both qualitative and quantitative characteristics. If investigated quality attributes, then their shares are calculated, and when studying quantitative ones, the average values ​​are determined.

Sample surveys allow us to solve various problems: studying the structure of realized demand, the structure of inventory, the characteristics and size of unsatisfied demand, the socio-economic composition of buyers, purchasing intentions, etc.

Questionnaire forms:

• - full-time;
• - correspondence.

Requirements for drawing up the questionnaire:

• Questions should be simple and understandable
• Questions must be clear
• Questions must be neutral
• * questions should go from simple to complex
• * questions should go from general to specific
• * questions must inspire confidence among respondents
• o issues that establish trust come first
• o in second place is the block of basic questions
• o in third place are control questions
• o at the end there are passport questions (about the individual) or company

The questionnaire is based on statistical methods selective observation. A necessary condition survey organizations are:

• · preliminary study of the general population;
• · assessment of its homogeneity (homogeneity)
• · sorting by main characteristics;
• · determination of the required number of respondents (sample)

A mechanical selection method in which the sample size is determined by the formula:

where n is the sample, t is the confidence coefficient, depending on the probability with which it can be guaranteed that marginal error does not exceed average error(with a probability of 0.99 it is equal to 3, more often e = 2), - the variance of the characteristic being studied, usually determined on the basis of experiment or analogues, - the maximum (ordinary) sampling error, N - the number of units of the population being studied.

Processing the results. When processing the results, various mathematical methods are used. The results are presented in the form of tables and graphs. During the analysis of the results, the probability of error and the corresponding confidence interval are determined. Finally, a report is written that sets out the facts with scrupulous accuracy and minimal influence from the analyst's own beliefs.

Analysis of results. Each answer is carefully analyzed. If the answer is obviously incorrect, it is impossible to understand anything from it, or the answer is definable, or the respondent answered for show or without knowing the subject, his answer is excluded.