We cannot deny the fact that everyone needs a sort of calculation in their daily life, including those who despise mathematics. Measuring the average numbers of calories that people eat in a day or how far people travel to go to the office is two of the examples. People need tools and methods to know exactly the answer to that question, and they will get what they want once they decide to learn about statistics.
The mathematical science defines statistics as a science to help people deal with data overload. It helps acquire, analyze, and collect data to know the real answer to certain issues. It also involves multiple sampling methods to ensure that only reliable data is collected. As those who despise mathematics often say that they do not need to deal with the subject since it is not related to their field of expertise, they need to know that statistics apply to many areas of knowledge. In short, the application proves to be much broader than what people initially assume.
Populations and Samples
It is amazing to see that statisticians are able to know the condition and calculation of the whole population only by depending on small portions of the population. It is what people refer to as sampling techniques. It basically collects and analyzes a small portion of the entire population, either random or designated, to analyze and know the real measurement of the whole population. Note that the term population does not refer to its general definition as a large group of people, but it is how statisticians refer to the entire data. As an example, doctors often take a blood sample to know the overall condition of a person. They do not need to take all the blood.
Data Collection
Now here comes the big question of how statisticians manage to collect the samples. Please note that they need good data to start the analysis, and it is not something that general people can do without knowing the basics. The methods used to take the samples are always the subject of critics as more and more people need a reliable way to begin the calculation.
There are three basic sampling methods that many people use, and they are simple random, stratified, and clustered methods. Each of them has its own characteristics and ideal conditions in which they can be used.