Page 149 - DMGT209_QUANTITATIVE_TECHNIQUES_II

Quantitative Techniques-II

Notes 3. If the population is homogeneous.

4. Also, there are circumstances when a census is not possible.

Example: Reactions to global advertising by a company.

8.2 Sampling Process

Sampling process consists of seven steps. They are:
1. Define the population.
2. Identify the sampling frame.
3. Specify the sampling unit.
4. Selection of sampling method.
5. Determination of sample size.

6. Specify sampling plan.
7. Selection of sample.
(1) Define the population: Population is defined in terms of:
(1) Elements
(2) Sampling units
(3) Extent
(4) Time.

Example: If we are monitoring the sale of a new product recently introduced by a
company, say (shampoo sachet) the population will be:
1. Element - Company’s product
2. Sampling unit - Retail outlet, super market
3. Extent - Hyderabad and Secunderabad

4. Time - April 10 to May 10, 2006
(2) Identify the sampling frame: Sampling frame could be (a) Telephone Directory (b) Localities
of a city using the municipal corporation listing (c) Any other list consisting of all sampling
units.

Example: You want to learn about scooter owners in a city. The RTO will be the frame,
which provides you names, addresses and the types of vehicles possessed.
(3) Specify the sampling unit: Individuals who are to be contacted are the sampling units. If
retailers are to be contacted in a locality, they are the sampling units.
Sampling unit may be husband or wife in a family. The selection of sampling unit is very
important. If interviews are to be held during office timings, when the heads of families
and other employed persons are away, interviewing would under-represent employed
persons, and over-represent elderly persons, housewives and the unemployed.
(4) Selection of sampling method: This refers to whether (a) probability or (b) non-probability
methods are used.

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