Talvir Singh is teaching live on Unacademy Plus
TARGET JRF 2018 LAST MINUTE REVISION 30 MOST IMPORTANT TOPICS PAPER 1 TARGET 80+
5 PRINCIPLES 1) Law of statistical regularity 2) Principle of inertia of large number . 3) Principle of persistence of small numbers . 4) Principle of validity . 5) Principle of optimizatiorn
Principle of 'Statistical Regularity . The principle of statistical regularity is derived from the theory of probability in mathematics. According to this principle, when a large number of items is selected at random from the universe, then it is likely to possess the same characteristics as that of the entire population. This principle asserts that the sample selection is random, i.e. every item has an equal and likely chance of being selected. It is believed that sample selected randomly and not deliberately acts as a true representative of the population. Thus, this principle is characterized by the large sample size and the random selection of a representative sample.
Principle of 'Inertia of Large Numbers The principle of Inertia of large numbers states that the larger the size of the sample the more accurate the conclusion is likely to be. This principle is based on the notion, that large numbers are more stable in their characteristics than the small numbers, and the variation in the aggregate of large numbers is insignificant. It does not mean that there is no variation in the large numbers, there is, but is less than in the smaller numbers. . Thus, both the principles talk about the sample size i.e. the larger it is, the larger is the accuracy of the results obtained
Principle of persistence of small numbers According to this principle if some of the items in a population possess markedly distinct characteristic from the remaining items then this tendency would be revealed in the sample value also rather this tendency of persistence will be there even if the population size is increased or even in the case of large sample.
Principle of Validity .A sample design is termed as valid if it enables us to obtain valid tests & estimates about the population parameters.