Census method and sampling method Advantages and Demerits

2.  In Statistics or Research Methodology, the basis of all
statistical calculations or interpretation lies in
the collection of data. There are two methods of
data collection.
 These two methods are the Census method and
Sampling method.
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3.  Census method is where all members of the
population are studied.
 A population refers to the set of all observations under
concern. For example, if you want to carry out a survey
to find out student’s feedback about the facilities of
your school, all the students of your school would form
a part of the ‘population’ for your study.
 In our country, the Government conducts the Census
of India every ten years. The Census appropriates
information from households regarding their incomes,
the earning members, the total number of children,
members of the family, etc.
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4.  Intensive study
1. It provides intensive and in-depth information covering
many facets of the problems.
2. For example: In a population census, Not only the
number of persons is counted, but the information is also
collected on various other parameters like,- The number
of males and females, Age, Education, Marital Status,
Occupational level, Income Health Conditions, etc.
 Results are more accurate and reliable
1. Since in this type of investigation every item of the
universe is taken into account, the conclusions are more
accurate and reliable.
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5.  Costly method - Since the data are obtained for or
from each & every unit of the population, it is a very
expensive method of investigation, especially in case
of large size of the population.
 Needs more time and manpower - Since a large
volume of data is to be collected, more time and
manpower is required for its collection, analysis and
interpretation.
 Not suitable for the large population - This method
is meaningless in case of an infinite universe where the
number of items is unlimited.
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6.  The population contains units with some similar characteristics
on the basis of which they are grouped together for the study.
 In the case of the Census of India, for example, the common
characteristic was that all units are Indian nationals. But it is not
always practical to collect information from all the units of the
population.
 It is a time-consuming and costly method.
 Thus, an easy way out would be to collect information from
some representative group from the population and then
make observations accordingly.
 This representative group which contains some units from the
whole population is called the sample.
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7.  Economical i.e. Low cost - It is more economical than the
Census Method, as the task of collection and analysis of
data is limited only to a small sample i.e. a few units of the
population.
 Quick results - In this method, only a few units are
analyzed so, we get quicker results.
 Indispensable Or greater scope - Sampling becomes
indispensable where census method is impracticable.
 Scientific approach - Sampling Method is more scientific
than the Census Method as it is possible to determine the
extent of reliability of its results.
 Follow up - Due to the small size of the sample, it is
possible to cross-check the data to test the reliability.
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8.  Difficult to achieve cent per cent accuracy.
 Bias in the selection of sample - In such cases, the
selected Sample may not be the best representative of
Population.
 Difficult to select a sample having all the
characteristics of the population.
 The need for specialised knowledge & training.
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9. Basis Census method Sampling method
Nature of
enquiry
The extensive enquiry is
conducted at each and every
unit of the population is
studied.
The limited enquiry is
conducted as only a few units
of the population are studied.
Economy More Time, Money & Labour -
It requires a large amount of
money, time and labour.
Less Time, Money &
Labour Relatively less money,
time, and labour are required.
Suitability It is more suitable if the
population is
heterogeneous in nature.
It is more suitable if the
population is homogeneous in
nature.
Reliability
and accuracy
Results are quite reliable and
accurate under the Census
method.
The under sampling
method results and less
reliable because a high degree
of accuracy is not achieved.
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10. Jyoti Rastogi (Assistant Professor) 10
Basis Census method Sampling method
Organization
and
supervision
It is very difficult to organize
and supervise the census
method.
The sampling method
is comparatively easy to
organize and supervise.
Verification Under this method results of
the investigation cannot be
verified.
Under this method, results
can be tested taking out
another small sample.
Nature of
method
Census method is an old
method of investigation and
it is not a very
scientific method.
The sampling method is a new
and practicable method, It is
a scientific method.

11. Jyoti Rastogi (Assistant Professor) 11