Census or Complete Enumeration
A survey, which includes every element of the population, is known as Census or the Method of Complete Enumeration. If certain agencies are interested in studying the total population in India, they have to obtain information from all the households in rural and urban India. The essential feature of this method is that this covers every individual unit in the entire population. You cannot select some and leave out others. You may be familiar with the census of India. Which is carried out every ten years.
A house-to-house enquiry is carried out, covering all households in India. Demographic data on birth and death rates, literacy, workforce, life expectancy, size and composition of population, etc. are collected and published by the Registrar General of India. The last Census of India was held in February 2001
Courtesy: NCERT Textbooks
According to the Census 2001, population of India is 102.70 crore. It was 23.83 crore according to Census 1901. In a period of hundred years, the population of our country increased by 78.87 crore. Census 1981 indicated that the rate of population growth during 1960s and 1970s remained almost same. 1991 Census indicated that the annual growth rate of population during 1980s was 2.14 per cent, which came down to 1.93 per cent during 1990s according to Census 2001. βAt 00.00 hours of first March, 2001 the population of India stood at 1027,015,247 comprising of 531,277,078 males and 495,738,169 females. Thus, India becomes the second country in the world after China to cross the one billion mark.β
- Population or the Universe in statistics means totality of the items under study.
- Thus, the Population or the Universe is a group to which the results of the study are intended to apply.
- A population is always all the individuals/items who possess certain characteristics (or a set of characteristics), according to the purpose of the survey.
- The first task in selecting a sample is to identify the population. Once the population is identified, the researcher selects a Representative Sample, as it is difficult to study the entire population.
- A sample refers to a group or section of the population from which information is to be obtained.
- A good sample (representative sample) is generally smaller than the population and is capable of providing reasonably accurate information about the population at a much lower cost and shorter time.
- Suppose you want to study the average income of people in a certain region. According to the Census method, you would be required to find out the income of every individual in the region, add them up and divide by number of individuals to get the average income of people in the region.
- This method would require huge expenditure, as a large number of enumerators have to be employed.
- Alternatively, you select a representative sample, of a few individuals, from the region and find out their income.
- The average income of the selected group of individuals is used as an estimate of average income of the individuals of the entire region.
- Research problem: To study the economic condition of agricultural labourers in Churachandpur district of Manipur.
- Population: All agricultural labourers in Churachandpur district.
- Sample: Ten per cent of the agricultural labourers in Churachandpur district. Most of the surveys are sample surveys. These are preferred in statistics because of a number of reasons. A sample can provide reasonably reliable and accurate information at a lower cost and shorter time. As samples are smaller than population, more detailed information can be collected by conducting intensive enquiries. As we need a smaller team of enumerators, it is easier to train them and supervise their work more effectively. Now the question is how do you do the sampling? There are two main types of sampling, random and non-random. The following description will make their distinction clear.
- In which years will the next Census be held in India and China?
- If you have to study the opinion of students about the new economics textbook of class XI, what will be your population and sample?
- If a researcher wants to estimate the average yield of wheat in Punjab, what will be her/his population and sample?