To start with the introduction on Statistics, we should know what it means. These words, Statistics and static are used very commonly in our day to day conversation but we don’t know the difference between them. Why should we start with the difference between Statistic and Statistics? Because, the difference uncovers the definition of statistics and clears us from the confusion.
There is a very common misinterpretation about the word in singular sense- “STATISTIC” and in plural sense “STATISTICS”.
To deviate a bit more, and to know the difference, we first need to know what a SAMPLE is and what is a POPULATION.
Difference between sample and population
When we think of Population, the first thing that comes to our mind is population of a country, a state or any particular geographical area. In statistics, Population is just that.
Population consists of ALL the people or objects or items that are included in our study or the topic of our research.
E.g. I want to study the effectiveness of extra classes in school students of India.
My population consists of ALL SCHOOL GOING CHILDREN IN INDIA.
It is almost impossible and impractical for the researcher to reach the whole population. No doubt that the best results are obtained if each and every item of our population is covered but to be feasible and quick, researchers RANDOMLY select a PART of the population which is called a SAMPLE.
When we obtain the results from the Population, it is called a Parameter and when we obtain results from a Sample, it is called Statistic.
Coming back to the difference,
STATISTIC is the score of each individual or a singular data.
STATISTICS is therefore, the process of designing, comparing, interpreting and analysing data.
Statistics is concerned with the sample and not the population as population is almost impossible to reach.
The above sentence tells us the IMPORTANCE of Statistics.
Statistics is used for generalization and prediction of the behaviour of our population on the basis of the results of our sample PLUS CONDITIONS APPLIED (Just as the whole of population is impossible to reach, similarly it’ll be a false statement if we say that our population will behave 100% as accurate as our sample. These conditions are small margins we leave for errors that can arise due to numerous factors like unreliability of the results due to extraneous variables, non-randomization of the sample, biases from the side of the researcher, inaccuracy of the tool to exactly measure what we want to measure etc.)
Therefore, Statistics provides us a direction not 100% accuracy about the characteristics of our population.