What Are The Basic Concepts Of Statistics

Statistics is a branch of mathematics that studies variability and also the process that calculates variability by following the laws of probability and using models. We know that statistics are necessary to conduct and understand surveys. What are the basic concepts of statistics?

To focus on the basic concepts of statistics, we must turn to descriptive statistics. This branch deals with the description of the experimental data.

In concrete terms, this involves collecting, organizing and analyzing data. The data describes a set of characteristics of a set of items that belong to a population.

Basic concepts of statistics

According to Professor Ignacio Cascos of Charles III University in Madrid, these are some of the basic concepts that everyone should know:

1. Population

A population is a well-defined set of similar subjects with certain characteristics that are of interest to the observers. This aspect can be finite or infinite. Therefore, the size of the population is the number of items it contains. It is usually denoted by N.

If the population is very large, it can be very expensive to conduct the study. So in some cases it is impossible to consider every element. Therefore, researchers usually select a few elements from the population or a sample.

2. Items or Objects

An item or object is an individual element of the population. Now these elements don’t necessarily have to be people. In psychology, however, that is usually the case.

3. Sample

A sample is a collection of items from the population that best represents its characteristics. If the sample size reflects the characteristics of the population, the sample is representative.

Moreover, the sample size is the number of items it includes. We denote sample size with n . If the sample and the population size coincide, this is referred to as a complete census.

4. Variables

A variable (X) is a symbol that represents a characteristic, number, or quantity of the population that researchers can measure or count. Data(r) is the value that can change within a variable (hence the name). The value depends on the item it measures.

Variable Types

Qualitative variable

This kind of variable gets the values ​​corresponding to unquantifiable qualities of the items. So you cannot say that one variable is worth more than the other.

An example of this type of variable is, for example, gender. These variables are called qualitative because the differences between these variables are the qualities or characteristics.

Ordinal variable

An ordinal variable can be divided into categories. In addition, the researchers can rank or order them based on their value. If you had qualitative variables, you could rank them. Consider, for example, school grades. A 10 is better than a 9. A 9 is also better than a 4.

Quantitative variable

Quantitative variables are given numerical values. This means that you can measure them in numbers. There are two kinds:

• Discrete variable. The set is finite or countable. For example, the number of children in a family.
• Continuous variable. The set is infinite or uncountable. For example time.

Position measurements

In descriptive statistics, you can determine the position of your data by using position measurements.

Center measurements

Center measures or central tendencies are typical or representative values ​​of a data set. Therefore, the intent is to summarize all data with a single value.

The most common measures of central tendencies are mode (qualitative variables), median (categorical variables), and mean (quantitative variables).

• mode. The mode is the item that is displayed the most. If there is more than one of these values, the variable is multimodal. In addition, you can calculate the mode for any type of variable.
• Median. You calculate this for categorical variables. Specifically, at least half of the data is less than or equal to the median. Similarly, at least half of the data is also greater than or equal to the median. Therefore, if there is more than one median, you must take the midpoint between the largest and smallest median. This will be the value that appears in the sample and serves as the median.
• Average. This is the most common and best known value. You need quantitative variables to calculate it. The mean is the geometric center or place where the data meet. Something strange happens with the mean, because it may not be representative of the sample, but it can’t really represent an actual value of the sample either. In other words, it is possible that this value does not exist in the sample.

Final Thoughts

While many more concepts are used in statistics, these are perhaps the most basic. With their help, you can organize and calculate statistics and data.

So basic concepts of statistics are great tools for researchers and the scientific community. Statistics give you a complete overview of the results of a survey.