Statistical Regularity

At present we are living in an age of data. Daily we generating a bulk of data and companies are trying to analyze them to understand our nature. To do this kind of analysis they need data analysts or data scientists or data engineers (all do the same job, you can differentiate them only by their designations and salaries). In data analysis, they use different statistical methods in different situations according to different requirements. Statistical regularity is something that lies in the heart of each and every statistical method, Unfortunately, we don't find this topic in most of our available textbooks. I have tried to explain Statistical regularity in the following video lectures with my limited capacity, links are provided below:

Statistical Regularity Part I - https://drive.google.com/file/d/15g4-5ABRkUoGVGVZ2HSUqDQ-7Bk--g-w/view?usp=sharing

Statistical Regularity Part II - https://drive.google.com/file/d/1MSG2AplunqpNQvJxIp3nV4BjREKtHtpp/view?usp=sharing