Census and sample
surveys, advantages and disadvantages
A
complete enumeration,
often known as a census
survey, is the comprehensive count of all population units for a specific characteristic.Comprehensive enumeration will normally need a significant amount of money, labor, and time, and there will be many cases where comprehensive enumeration is impossible due to restricted
resources. There are also cases where enumerating all units is impractical due to their perishable
nature, in which case selecting
a
few units will be useful. When a subset of the population, known as a sample, is selected and investigated, the process is known as sample enumeration or sample survey.
A sample
survey is usually less expensive than a census
survey, and it will provide the needed information in less time. This does not imply that the economy
is the sole consideration when conducting a sample
poll. It is critical that results
remain accurate. Occasionally, the sample survey
technique is used to check the results of a census
survey.
It
is commonly known that in many cases, a well-conducted sample
survey can produce far more exact results than a census survey. Mahalanobis (1950),
Yates (1953), Zarkovich
(1961), and Lahiri (1963) have explored the relative advantages and disadvantages of sample
surveys compared to census surveys. Cochran (1977) has very clearly demonstrated
the
advantages of sample surveys
over census surveys. In short, they are:
(i) survey costs are lowered,
(ii) increased speed of outcomes,
(iii) more accurate
results,
(iv)
increased scope, and
(v)
adaptability.
Fisher (1950)
summarized the advantages of sample
surveys over census
surveys as follows:
"I have made four claims for the sampling procedure. About the first three, adaptability, speed and economy, I need say nothing further.Too many examples are already available to show how much the method has to give in these ways. But, why do I say that it is more scientific than the only procedure with which it may sometimes be in competition, complete enumeration? The answer, in my view, lies in the primary process of designing and planning an enquiry by sampling. Rooted as it is in the mathematical theory of the errors of random sampling, the idea of precision is from the first in the forefront. The director of the survey plans from the first for a predetermined and known level of precision; it is a consideration of which he never loses sight, and precision actually attained, subject to well-understood precautions, is manifest from the results of the enquiry."
Despite the advantages listed above, sample surveys
are not always
preferred over census surveys. Sampling theory
has its own restrictions, and the advantages
of sampling over thorough enumeration can be obtained only if ;
(i) the units are drawn in a scientific way,
(ii) an appropriate sampling
technique is utilized, and
(iii) the sample units'
sizes are acceptable. If information
PRINCIPLES OF SAMPLING THEORY
The main aim of sampling theory is to make sampling
more effective so that the answer to a particular question is given in a valid,
efficient and economical way. The theory of sampling is based on three important
basic principles:
(i) Principle of Validity,
(ii) Principle of Statistical Regularity, and
(iii) Principle of Optimization.
The purpose of a census is to gather information from every member of a specified population. It is conducted periodically to provide thorough, demographic, social, and economic data, typically every ten years in many nations. A census's primary benefit is its comprehensiveness; by striving for a thorough count, it reduces sampling errors and offers in-depth information on a range of demographic variables. This information is crucial for political representation since it establishes the number of legislative seats allotted to each region and affects the distribution of public funds, which go toward infrastructure, healthcare, and education. There are obstacles involved in conducting a census, notwithstanding its benefits. It is necessary to address concerns like mistrust, language challenges, and accessibility for marginalized communities in order to ensure accurate participation. In order to promote participation and make the process more inclusive, governments frequently implement outreach initiatives and make use of technology.
Sampling
Contrarily, sampling entails choosing a subset of people from a broader group in order to make inferences about that population. When conducting a full census is not feasible because of financial, logistical, or time restrictions, this approach is frequently used. Researchers can reasonably deduce trends and characteristics about the total population by carefully choosing a representative sample. There are several methods for sampling, such as systematic, stratified, and random sampling. Random sampling ensures that every individual has an equal chance of being selected, while stratified sampling divides the population into subgroups and samples from each to ensure representation across key demographics. While sampling might save time and resources, it brings the risk of sampling error—wherein the sample may not precisely reflect the population. This risk can be reduced by using suitable sample sizes and appropriate sampling methods. In conclusion, sampling and the census are both essential for gathering data; sampling offers a workable substitute for complete enumeration in situations where the census does not provide a complete picture of the population. While each approach has advantages and disadvantages, they all make substantial contributions to resource allocation, research, and policy making.
Census and sampling are fundamental methods used in data collection while this year the common goal of gathering information about a population, they differ significantly in their approach and scope.
Advantages of census
Accuracy:. Consists can provide highly accurate data as the capture information from every individual.
Completeness: The ensure that no one is missing leading to complete representation of the population.
Detail census: can collect and wide range of detailed information about individuals and households
Disadvantages of census
Cost; conducting census can be extremely expensive especially for large population.
Time consuming; the process of collecting data from every individual is time consuming and resource intensive.
Burdensome; It can place a significant burden on respondent and may lead to data quality issues.
Sampling
Sampling involves selecting a subset of individuals or elements from a population to represent the entire group. By studying the sample, researchers can draw inferences about the characteristics of the population.
Advantage of sampling;
Cost effective; sampling is generally less expensive than conducting a Census, especially for large populations.
Time efficient; it can be completed in a shorter amount of time compared to a Census.
Disadvantages of sampling
Sampling error; There is always a risk of sampling error which is the difference between the sample results and true population values.
Bias; If the sample is not representative of the population it can lead to bias results.
Limited detail; sampling may not provide as much detail as census, especially for smaller populations.
