• Data collection is a term used to describe a process of preparing and collecting data
  • Systematic gathering of data for a particular purpose from various sources, that has been systematically observed, recorded, organized.
  • Data are the basic inputs to any decision-making process in business.


  • Data can be defined as the quantitative or qualitative value of a variable (e.g. number, images, word, figures, facts, ideas)
  • It is a lowest unit of information from which other measurements and analysis can be done.
  • Data is one of the most important and vital aspects of any research study.


The purpose of data collection is-

  • To obtain information
  • To keep on record
  • To make decisions about important issues,
  • To pass information on to others

Type of Data

Primary Data- Are those which are collected a fresh and for the first time and thus happen to be original in character and known as Primary data.

Secondary Data- Are those which have been collected by someone else and which have already been passed through the statistical process are known as Secondary data.

Primary Data

  • PRIMARY DATA are those which are collected a fresh and for the first time and thus happen to be original in character and known as Primary data.
  • Primary data has not been changed or altered by human being; therefore, its validity is greater than secondary data.
  • Primary Data Collected by investigator himself for the purpose of a specific inquiry or study. The data is original in character and highly representative and unbiased.

Methods of Primary Data Collection: -

 A) Observation

  B) Interviewing-

  • Personal interviews 
  • Telephonic   Interview



A) Observation

Observation method is a method under which data from the field is collected with the help of observation by the observer or by personally going to the field.


  • Subjective bias eliminated
  • Researcher gets Current information
  • Independent to respondent’s variable


  • It is expensive method
  • Time consuming
  • Limited information
  • Unforeseen factors may Interfere with observational task
  • Respondents opinion cannot be recorded on certain subject


  1. Structured and Unstructured Observation
  • When observation is done by characterizing style of recording the observed information, standardized conditions of observation, definition of the units to be observed, selection of pertinent data of observation then it is structured observation
  • When observation is done without any thought before observation then it is unstructured observation
  1. Participant & Non-Participant Observation
  • When the Observer is member of the group which he is observing then it is Participant Observation
  • In participant observation Researcher can record natural behaviour of group, Researcher can verify the truth of statements given by informants in the context of questionnaire, Difficult to collect information can obtain through this method but in this researcher may lose objectivity of research due emotional feelings. Prob. of control in observation isn’t solved.
  1. Non-Participant Observation
  • When observer is observing people without giving any information to them then it is non participant observation
  1. Controlled & Uncontrolled Observation
  • When the observation takes place in natural condition i.e. uncontrolled observation. It is done to get spontaneous picture of life and persons
  •  When observation takes place according to definite pre-arranged plans, with experimental procedure then it is controlled observation generally done in laboratory under controlled condition.


  • Interview method is direct method of collection of data, which is based on interview. It is the most important methods we can know the views and ideas of other persons. it is a method of social interaction
  • Interview can be conducted through personal and telephone.


  1. PERSONAL INTERVIEWS: The interviewer asks questions generally in a face to face contact to another person.

Types of Personal Interview: -

a. Structured Interview-

  • Predetermined question
  • Standardized techniques of recorded
  • Interviewer follows rigid procedure
  • Time required for such interview is less than non-structured manner interview
  • Not necessary of skill or specific knowledge

b. Unstructured Interview: -

  • No Predetermined questions
  • No Standardized techniques
  • Interviewer has freedom to ask, omit, add any questions
  • Ask questions without following sequence
  • Deep knowledge & skill required
  • Analysis of data is difficult prescribed manner intact to the other person or persons.

Merits of Interview: -

  • Information at greater depth
  • Flexibility of restructuring the Questionnaire
  • Interviewer by his skill can come over resistance
  • Non-Response generally low
  • Samples can control more effectively
  • Personal information can be obtained

De Merits of Interview: -

  • Expensive method
  • Respondent may give bias information
  • Some Executive people are not approachable so data collected may be inadequate
  • Takes more time when samples are more

2.Telephonic Interview: -

  • Telephone interview the information is collected from the respondent by asking him question on the phone is called as telephone interview.
  • The combination of telephone and computer has made this method even more popular


  • Flexible compare to mailing method
  • Faster than other methods
  • Call-backs are simple and economical also High response than mailing method.
  • Interviewer can explain requirements more easily
  • No field staff is required
  • Wider distribution of sample is possible


  • Little time is given to respondents
  • Survey is restricted to respondents who have telephones
  • Bias information may be more
  • Very difficult to make questionnaire because it should short and to the point

Focused interviews: attention is focused on the given experience of the respondent and its possible effects.

Other types of Interview: -

  • Group interviews: a group of 6 to 8 individuals is interviewed.
  • Individual interviews: interviewer meets a single person and interviews him.
  • Selection interviews: done for the selection of people for certain jobs.
  • Depth interviews: it deliberately aims to elicit unconscious as well as extremely personal feeling and emotions. This is designed to encourage free expression of affectively charged information.


  • Questionnaire Technique Gather data by asking questions from people who are thought to have the desired information. When information is to be collected by asking questions to people who may have the desired data, a standardized form called questionnaire is prepared.
  • The questionnaire has a list of questions to be asked in a desired sequence and spaces in which the respondents record the answers.

Open ended & Closed ended Questions

  1. Open ended
  • It requires written responses from the subjects and allow respondent to answer in their own words.
  • Easy to construct.
  • Difficult to analyze.
  • Commonly used in qualitative research.
  • Time consuming
  • They provide insightful and natural response
  • Flexible and applicable to wide range of participants.
  1. Closed ended Questions-
  • It requiring only selecting the response from given alternatives (pre- designated, developed by researcher)
  • Difficult to construct
  • Easy to analyze and compare
  • Commonly used in quantitative studies.
  • Time- saving
  • Fixed and artificial
  • Relevant data
  • More objective

Merits of Questionnaire: -

  • Low cost even the geographical area is large to cover
  • Answers are in respondents’ word so free from bias
  • Adequate time to think for answers
  • Non approachable respondents may be conveniently contacted
  • Large samples can be used so results are more reliable

Demerits of Questionnaire: -

  • Low rate of return of duly filled questionnaire.
  • Can be used when respondent is educated and co-operative.
  • people can lie and answer the question vaguely.
  • questionnaire provide only superficial information.
  • Difficult to know the expected respondent have filled the form or it is filled by someone else.
  • Slowest method of data collection.


It is a Performa containing a set of question. This Performa is filled by enumerators who are specially identified for the purpose. The enumerators are persons acting under the direction of researchers

 Requisite of a good schedule-

  • Accurate communication
  • Schedules must be attractive

Others Methods’


  • A research technique in which information gathered from s sample of people by use of questionnaire.
  • A method of data collection based on communication with a respective sample of individuals.
  • A formal list of questionnaires is prepared.


  • Information is collected from a group of people.
  • The main way in which the information is collected through asking questions.
  • Information is collected from a sample rather than from every member of the population.

Advantages of survey method

  • Relatively easy to administer.
  • Can be developed in less time (compared to other data-collection methods).
  • Cost-effective, but cost depends on survey mode.
  • Can be administered remotely via online, mobile devices, mail, email, kiosk, or telephone.
  • Capable of collecting data from a large number of respondents.
  • Numerous questions can be asked about a subject.
  • A broad range of data can be collected (e.g., attitudes, opinions, beliefs, values, behavior, factual.


  • Respondents may not feel encouraged to provide accurate, honest answers.
  • Respondents may not feel comfortable providing answers that present themselves in a unfavorable manner.
  • Respondents may not be fully aware of their reasons for any given answer because of lack of memory on the subject, or even boredom.
  • Surveys with closed-ended questions may have a lower validity rate than other question types.

Experiments Method

  • Experiments require an artificial or natural setting in which to perform logical study to collect data. Experiments are more suitable for medicine, psychological studies, nutrition and for other scientific studies.
  • In experiments the experimenter has to keep control over the influence of any extraneous variable on the results.


It is essentially an intensive investigation of the particular unit under consideration. Its important characteristics are as follows:

  • The researcher can take one single social unit or more of such units for his study purpose.
  • The selected unit is studied intensively i.e. it is studied in minute details.


 In this method, data is collected from the same sample respondents at some interval either by mail or by personal interview. This is used for studies on-

  • Expenditure Pattern
  • Consumer Behaviour
  • Effectiveness of Advertising
  • Voting Behaviour and so on
  • Secondary data are those which have already been collected by someone else and which have through some statistical analysis.
  • Data that are already available.
  • Publications of Central, state, local government Technical and trade journals Books, Magazines, Newspaper, Reports & publications of industry, bank, stock exchange Reports by research scholars, Universities, Public Records 

Before using Secondary data, researcher must check -

  • Reliability the data
  • Suitability of data
  • Adequacy of data

Difference between Primary and Secondary data

Primary data

Secondary data

  • Real time data
  • Past data
  • Sure, about sources of data
  • Not sure about sources of data
  • Costly and time-consuming process
  • Cheap and no time-consuming process
  • More flexible
  • Less flexible
  • Avoid biasness of response data
  • Cannot know in data biasness or not


  • Type of research subject
  • The nature of phenomenon under study
  • The purpose of the research study
  • Size of the study sample
  • Distribution of target population
  • Time frame of the study
  • Literacy level of the subject
  • Availability of resources and manpower