A census method is that process of the statistical list where all members of a population are analysed. The population relates to the set of all observations under concern. For instance, if you want to carry out a study to find out student’s feedback about the amenities of your school, then all the students of your school would form a component of the ‘population’ for your study.
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A sampling method is a process for choosing sample members from a population. Three (3) common sampling methods are:
- Simple random sampling
- Stratified sampling
- Cluster sampling
Census method and its advantages
|Q.1. Explain the census method of collection of data. Give its advantages and disadvantages.|
|(A) Census method||● A statistical investigation in which the data are collected for each and every element/unit of the population is termed as census method.
● It is also known as ‘complete enumeration’ or ‘100% enumeration’ or ‘complete survey’.
● It is useful when case intensive study is required or the area is limited.
1. Demographic data on birth and death rates, literacy, workforce, life expectancy, size and composition of a population
2. The census of India is conducted every 10 years.
|(B) The following are the advantages of the census method.|
|(1) Intensive study||● It provides intensive and in-depth information covering many facets of the problems.
● 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.
|(2) Results are more accurate and reliable||● Since, in this type of investigation, every item of the universe is taken into account, the conclusions are more accurate and reliable.|
|(B) The following are the disadvantages of the census method.|
|(1) Costly method||● Since the data are obtained for or from each and every unit of the population, it is a very expensive method of investigation, especially in case of a large population size.|
|(2) 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.|
|(3) Not suitable for the large population||● This method is meaningless in the case of an infinite universe where the number of items is unlimited.|
Sampling method and its advantages
|Q.2. Explain the sampling method of collection of data. Briefly discuss its advantages and disadvantages.|
|(A) Sampling method||● The sampling method is the one in which only some of the representative items of the population are selected and the data are collected from these.
● Instead of collecting information for and from all the units of population, we select a sample, i.e., only a few items of the population.
● Conclusions derived from the small sample are generalised for the whole population.
|(B) The following are the advantages of the sampling method.|
|(1) 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.|
|(2) Quick results||● In this method, only a few units are analysed, hence we get quicker results.|
|(3) Indispensable or greater scope||● The sampling method becomes indispensable, whereas the census method is impracticable. Example:
● If the life of bulbs is to be tested by the manufacturer
● If the quality of nuts and bolts is to be tested
● If blood test is to be carried out
● If the quality of prints is to be tested while printing books
|(4) Scientific approach||● The sampling method is more scientific than the census Method, as it is possible to determine the extent of reliability of its results.|
|(5) Follow up||● Due to the small size of the sample, it is possible to cross-check the data to test the reliability.|
|(6) Helpful in checking census results||● Due to scientific nature, the sampling method can be used to cross-check the results of the census method.|
|(C) The following are the disadvantages of the sampling method.|
|(1) Difficult to achieve cent percent accuracy||● The conclusions of the sampling method are based only on the results of a few items taken from the whole population. Thus, these may not be cent percent correct.|
|(2) Bias in the selection of sample||● If the investigator is biased, then he might select a sample deliberately.
● In such cases, the selected sample may not be the best representative of the population.
|(3) Difficult to select a sample having all the characteristics of the population||● In practice, it is very difficult to obtain a sample that truly represents the population.
● A sample may not have all the characteristics of the population.
|(4) Need for specialised knowledge and training||● It is a special technique and beyond the capacity of every person.
● Its use requires specialised knowledge and training.
Difference between Census and Sampling Method
|Q.3. Distinguish between census method and sampling method.|
|Parameters||Census Method||Sampling Method|
|(1) Nature of enquiry||The extensive enquiry is conducted at each and every unit of the population.||The limited enquiry is conducted as only a few units of the population are studied.|
|(2) Economy||More Time, Money, and Labour It requires a large amount of money, time, and labour.||Less Time, Money, and Labour Relatively less money, time, and labour are required.|
|(3) Suitability||It is more suitable if the population is heterogeneous in nature.||It is more suitable if the population is homogeneous in nature.|
|(4) Reliability and Accuracy||The results are quite reliable and accurate under the census method.||The results of the sampling method are less reliable because a high degree of accuracy is not achieved.|
|(5) Organisation and Supervision||It is very difficult to organise and supervise the census method.||The sampling method is comparatively easy to organise and supervise.|
|(6) Verification||Under this method, the results of the investigation cannot be verified.||Under this method, the results can be tested by taking out another small sample.|
|(7) Nature of method||The census method is an old method of investigation and not a very scientific method.||The sampling method is a new and practicable method. It is a scientific method.|
The above-mentioned concept is for CBSE Class 11 Statistics for Census Method and Sample Method. For solutions and study materials for Class 11 Statistics, visit our website or download the app for more information and the best learning experience.