1. Rai University , May 2015 Ph.D. Coursework of Research Methodology
Dr Kishor Bhanushali
Associate Professor
Unitedworld School of Business
Mob:
Rai University , May 2015 Ph.D. Coursework of Research Methodology

2. Sampling Fundamentals

3. Sampling
Sampling may be defined as the selection of some part of an aggregate or totality on the basis of which a judgement or inference about the aggregate or totality is made.
In other words, it is the process of obtaining information about an entire population by examining only a part of it.

4. NEED FOR SAMPLING Save time and money Accurate measurements
Only way for infinite population
Only choice when a test involves the destruction of the item
Sampling usually enables to estimate the sampling errors and, thus, assists in obtaining information concerning some characteristic of the population.

5. SOME FUNDAMENTAL DEFINITIONS
Universe/Population
Sampling frame
Sampling design
Statistics and parameters
Sampling error
Confidence level and significance level
Sampling distribution

6. IMPORTANT SAMPLING DISTRIBUTIONS
Sampling distribution of mean
Sampling distribution of proportion
Student’s t-distribution
F distribution
Chi-square distribution

7. CENTRAL LIMIT THEOREM
When sampling is from a normal population, the means of samples drawn from such a population are themselves normally distributed
The significance of the central limit theorem lies in the fact that it permits us to use sample statistics to make inferences about population parameters without knowing anything about the shape of the frequency distribution of that population other than what we can get from the sample.

8. CONCEPT OF STANDARD ERROR
The standard deviation of sampling distribution of a statistic is known as its standard error (S.E) and is considered the key to sampling theory.

9. SAMPLE SIZE AND ITS DETERMINATION
Nature of universe
Number of classes proposed
Nature of study
Type of sampling
Standard of accuracy and acceptable confidence level
Availability of finance
Other considerations: (a) Nature of units, (b) size of the population, (c)size of questionnaire, (d) availability of trained investigators, (e)the conditions under which the sample is being conducted, (f) the time available for completion of the study.

10. Sampling Design

11. CENSUS AND SAMPLE SURVEY
A complete enumeration of all items in the ‘population’ is known as a census inquiry.
Highest level of accuracy
This type of inquiry involves a great deal of time, money and energy.
The respondents selected should be as representative of the total population as possible in order to produce a miniature cross-section.
The selected respondents constitute what is technically called a ‘sample’ and the selection process is called ‘sampling technique.
Researcher must prepare a sample design for his study i.e., he must plan how a sample should be selected and of what size such a sample would be

12. STEPS IN SAMPLE DESIGN Type of universe Sampling unit Source list
Size of sample
Parameters of interest
Budgetary constraint
Sampling procedure

13. CRITERIA OF SELECTING A SAMPLING PROCEDURE
Inappropriate sampling frame
Non-respondents
Indeterminancy principle
Natural bias in the reporting of data
While selecting a sampling procedure, researcher must ensure that the procedure causes a relatively small sampling error and helps to control the systematic bias in a better way.

14. CHARACTERISTICS OF A GOOD SAMPLE DESIGN
(a) Sample design must result in a truly representative sample.
(b) Sample design must be such which results in a small sampling error.
(c) Sample design must be viable in the context of funds available for the research study.
(d) Sample design must be such so that systematic bias can be controlled in a better way.
(e) Sample should be such that the results of the sample study can be applied, in general, for the universe with a reasonable level of confidence

15. DIFFERENT TYPES OF SAMPLE DESIGNS

16. COMPLEX RANDOM SAMPLING DESIGNS
Systematic sampling
Stratified sampling
Cluster sampling
Area sampling
Multi-stage sampling
Sampling with probability proportional to size
Sequential sampling

17. Methods of Data Collection

18. The primary data are those which are collected afresh and for the first time, and thus happen to be original in character
The secondary data, on the other hand, are those which have already been collected by someone else and which have already been passed through the statistical process

19. COLLECTION OF PRIMARY DATA
(i) observation method,
(ii) interview method,
(iii) through questionnaires,
(iv) through schedules, and
(v) other methods which include (a) warranty cards; (b) distributor audits; (c) pantry audits; (d) consumer panels; (e) using mechanical devices; (f) through projective techniques; (g) depth interviews, and (h) content analysis.

20. Observation Method
Most commonly used method specially in studies relating to behavioural sciences
Information is sought by way of investigator’s own direct observation without asking from the respondent
Subjective bias is eliminated, if observation is done accurately
Information obtained under this method relates to what is currently happening
Independent of respondents’ willingness to respond
Very limited information
Structured observation & Unstructured observation
Participant observation & non-participant observation
controlled & uncontrolled observation.

21. Personal interview Structured interviews & unstructured interviews
Focused interview
Clinical interview
Non-directive interview
Merits & demerits of interview methods
Pre-requisites and basic tenets of interviewing

22. Telephone interviews
This method of collecting information consists in contacting respondents on telephone itself. It is not a very widely used method, but plays important part in industrial surveys, particularly in developed regions.
Merits & demerits.

23. COLLECTION OF DATA THROUGH QUESTIONNAIRES
Questionnaire is sent (usually by post) to the persons concerned with a request to answer the questions and return the questionnaire
The respondents have to answer the questions on their own
Pilot Survey
Main aspects of a questionnaire :general form, question sequence and question formulation and wording

24. Essentials of a good questionnaire
Short and simple
Logical sequence moving from easy to more difficult question
Personal and intimate questions should be left to the end.
Technical terms and vague expressions capable of different interpretations should be avoided in a questionnaire
Open-ended should be avoided
Control questions in the questionnaire which indicate the reliability of the respondent
Questions affecting the sentiments of respondents should be avoided
Adequate space for answers
There should always be provision for indications of uncertainty, e.g., “Do not know,” “no preference” and so on
Brief directions with regard to filling up the questionnaire should invariably be given in the questionnaire itself
Physical appearance

25. COLLECTION OF DATA THROUGH SCHEDULES
schedules (proforma containing a set of questions) are being filled in by the enumerators who are specially appointed for the purpose
Enumerators explain the aims and objects of the investigation and also remove the difficulties which any respondent may feel in understanding the implications of a particular question or the definition or concept of difficult terms.
Enumerators should be trained

26. SOME OTHER METHODS OF DATA COLLECTION
Warranty cards
Distributor or store audits
Pantry audits
Consumer panels
Use of mechanical devices
Projective techniques :(i) Word association tests (ii) Sentence completion tests (iii) Story completion tests (iv) Verbal projection tests (v)Pictorial techniques(vi) Play techniques (vii) Quizzes, tests and examinations
Depth interviews
Content-analysis

27. COLLECTION OF SECONDARY DATA
(a) various publications of the central, state are local governments;
(b) various publications of foreign governments or of international bodies and their subsidiary organisations;
(c) technical and trade journals;
(d) books, magazines and newspapers;
(e) reports and publications of various associations
connected with business and industry, banks, stock exchanges, etc.;
(f) reports prepared by research scholars, universities, economists, etc. in different fields; and
(g) public records and statistics, historical documents, and other sources of published information

28. Characteristics of Secondary Data
Reliability of data
Suitability of data
Adequacy of data

29. SELECTION OF APPROPRIATE METHOD FOR DATA COLLECTION
Nature, scope and object of enquiry
Availability of funds
Time factor
Precision required

30. Thanks

31. Unitedworld School of Business
Thanks
Dr Kishor Bhanushali
Associate Professor
Unitedworld School of Business
Mob: