research methods module 3

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14MBA23

Research Methods – Module 3

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14MBA23 – Research Methods

Syllabus:

Sampling: Concepts- Types of Sampling -Probability Sampling – simple randomsampling, systematic sampling, stratifiedrandom sampling, cluster sampling -NonProbability Sampling – convenience sampling-judgemental sampling, snowball sampling-quota sampling – Errors in sampling.

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SAMPLING:

For a researcher, he needs to gather informationfor his study and he selects a part of thepopulation for his study, which resembles byCharacteristics, which the researcher wants tobe studied.

In simple language, Sample is a unit of the largequantity, it may be products or a part of apopulation required for the study.

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SAMPLING: CONCEPTS OF SAMPLING:

There may be a number of Concepts in Sampling which caninclude,

i) Population (all units in a region),

ii) Sampling Unit (Identifyable units in the population),

iii) Sampling Design (Samples selected based on their possibleprobabilities),

iv) Sampling frame (The design can be the specific populationlike Indian Villages or Illiterates and so on),

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v) Random Sample: (Explanation is not required),

vi) Non-Random Simple: (Explanation not required)

vii) Population Parameters: (What basis population can becalculated – Its the mean or its average and variance of thepopulation)

viii) Statistic, Estimator and Estimate: (It need to be calculative,statistical information/ data to be gathered)

ix) Sample Design: (Sample design will specify every possibleprobability of being drawn)

x) Sampling errors: (Sample error is difference between thestatistic used to estimate and the actual but unknown values ofthe parameters)

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What is mean, median and mode?

Mean – The average., Ex: 3, 4, 6, 1, 3, Add all and divide it givesthe mean. (Total/ No of units = Mean – 17/5 = 3.4 is the mean)

Median – The center number in the arranged series, Ex:3,4,6,1,3 shall be arranged into one 1,3,3,4,6, here in the fivenumbers, the middle number is 3 Hence 3 is the median,

Mode – The common number in the series, Ex: 3,4,6,1,3 thecommon number appearing the hightest time is 3 hence Modeis 3.

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SAMPLING:

Purpose/ Features of Sampling:

i) Lowering the cost (Economical),

ii) Greater accuracy of results (Reliable, Accuracy,

Stability, Scientific – Probability or Non-Probability),

iii) Speedy in data collection (Less Time Consuming),

iv) Availability of population for test,

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STEPS IN DEVELOPING SAMPLING PLAN:

i) Define the target population, (Characteristics)

ii) Select the data collection method, (Interview, Observation)

iii) Identify sampling frames needed, (Eligible Sampling Units)

iv) Select appropriate sampling method,(Probability or Non

Probability Method)

v) Determine necessary sample sizes and overall contactrates, (Sample size, Time and Money Reqd)

vi) Creating an operating plan for selecting sampling units,(How to reach the respondents)

vii) Execution of the operational plan.(Start with consistency and

control)

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Determination of Appropriate Sampling Design:

i) What's the research objective,

ii) What is the scope of the research,

iii) What are the availability of resources (Primary resources/secondary resources),

iv) What is the time required to perform the sampling,

The next is (After the collection of the sample data)

v) Is the target population knowledge adequate,

vi) Is the appropriate tools used for the sampling,

vii) Is the solution accurate.

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Factors influencing the sample size are:

i) Size of the population,

ii) Availability of the resources (Primary or secondary),

iii) Degree of accuracy desired,

iv) Homogeneity (Same) or Hetrogenity (Different) of thepopulation,

v) Nature of Study,

vi) Method of sampling adopted,

vii) Nature of respondents

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Merits and Demerits of sampling:

Merits of Sampling:

i) Sampling saves/ consumes less time,

ii) Sampling provides more information,

iii) Sampling provides information at less cost,

iv) Sampling is scientific,

v) Sampling results are reliable.

Demerits of Sampling: If proper place, time, respondents,techniques or tools, are selected wrong it has lots ofdemerits, like Inaccuracy, Misleading, or leads tocomplications and confusions.

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Errors in Sampling: Errors can be in two types: (a)

Biased and (b) Unbiased Errors

(a) Biased Errors are those errors due to bias of prejudice(unreasonable) on the part of the respondent or informant,or/ and on the part of the researcher in selection ofrespondent, or method of data collection.

(b) Unbiased Errors are those errors which is occuredaccidental without the knowledge of the researcher,

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SAMPLING:

Types of Sampling or Techniques inSampling:

i) Probability Sampling,

ii) Non-Probability Sampling.

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SAMPLING:

Types of Sampling

i) Probability Sampling (Non-Zero Probability),:

a) Simple Random Sampling,

b) Systematic Random Sampling,

c) Stratified Random Sampling,

d) Cluster Sampling,

e) Multi-Phase Sampling or Sequential Sampling,

f) Sampling with probability proposition to size.

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SAMPLING:

Types of Sampling

ii) Non-Probability Sampling,:

a) Convenience Sampling,

b) Judgment Sampling,

c) Quota Sampling,

d) Snowball Sampling,

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SAMPLING:

Types of Sampling - Probability Sampling,:

a) Simple Random Sampling:

Simple Random Sampling refer to the sampling techniquewhere the respondents are gathered randomly. In randomsampling this is done as,

i) Every respondent is equally qualified for the selectionchosen for the sample,

ii) Every respondent has the equal probability, indetermining the results.

Example: Out of 56 students, 10 were taken randomly.

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SAMPLING:


b) Systematic Random Sampling: Systematic RandomSampling is the sampling, where out of the targetpopulatio, sample is collected in a systematic manner.

Example: In the class attendance list, every fifth studentshall be taken for sampling,

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SAMPLING:


c) Stratified Random Sampling: Stratified RandomSampling, refers when the population is divided intocertain classes or social layers to form a individualsample.

Example: Sampling stratefied on the basis of caste orreligion or education or life style.

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SAMPLING:


d) Cluster Sampling: Cluster sampling is a probabilitysampling method in which the sampling units are dividedinto mutually exclusive and collectively exhaustivesubpopulation called Clusters.

Cluster sampling is 'Single Stage (One Stage)' and 'MultiStage (Several Stage)' Cluster Sampling, and ifdistributed geographically then it is 'Area Sampling'.

Cluster sampling may or may not have approximatenumber of elements/ subjects in each cluster.

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SAMPLING:


e) Multi-Phase Sampling: Multi-phase Sampling is alsocalled as Sequential Sampling and Double Sampling asthe first sample is taken for preliminary study and furtherthereon it is taken for more details and furtherinformations.

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SAMPLING:


f) Sampling with probability propositional to size:

This refers that the sampling where each sample is selectedramdomly or systematically or stratified, (as per theselection of the researcher), but each sample shall havethe same size, for samples tends to have a uniform study.

This sampling is less expensive and the process is more orless, like the simple random sampling.

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SAMPLING:

Types of Sampling

ii) Non-Probability Sampling,:

a) Convenience Sampling,

b) Judgment Sampling,

c) Quota Sampling,

d) Snowball Sampling,

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Types of Sampling

ii) Non – Probability Sampling:

a) Convenience Sampling:

i) Convenience Sampling is a Non-Probability Sampling.

ii) Convenience Sampling is the sampling where the researcher has thefreedom to choose sampling of his choice or convenient.

Iii) Convenience Sampling is usually performed during theExploratory Research Phase of a research project.

iv) Convenience Sampling is the method where the researcher is able tocollect informations quickly and efficienctly.

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Types of Sampling


b) Judgment Sampling: i) Judgment Sampling is a non-probability Sampling,

ii) Judgment Sampling is used in exploratory researchprocess,

iii) Judgment Sampling is selected on researcher's beliefs tomeet the research,

iv) Judgment Sampling is performed to collect informationwhich is advantageous to the researcher.

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Types of Sampling


c) Quota Sampling: i) Quota Sampling is a Non-ProbabilitySampling,

ii) Quota Sampling is selection on pre-specified quotas,

iii) Quota Sampling is selection based on Age, Sex, Occupation,Income or Rural or Urban and so on.

iv) Quota Sampling can be based on demographic specifications,like Nanjangud Area, Siddartha Lay out, MBA Students.,

v) Quota Sampling is done to ensure that the group/ quotaselected is able to adequately represent the study.

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Types of Sampling


d) Snowball Sampling: i) Snowball Sampling is anothernon-probability Sampling,

ii) Snowball Sampling is also called as 'Referral Sampling'.

iii) Snowball Sampling makes the respondent to refer anotherpotential respondent,

iv) Snowball Sampling is usually done where therespondents are small in number and unique to fulfill therequirement in the research.

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End of Module 3

research methods module 3

Education