What is Statistics? Types, Variance, and Bayesian Statistics

  • Riya Kumari
  • Nov 10, 2020
  • Statistics
  • Updated on: Feb 11, 2021
What is Statistics? Types, Variance, and Bayesian Statistics title banner

Statistics is the science related to creating and reading strategies for gathering, dissecting, interpreting, and introducing experimental information. 


Statistics is an exceptionally interdisciplinary field. Research in statistics discovers applicability in essentially all logical fields and exploration inquiries in the different logical fields persuade the improvement of new factual strategies and hypotheses.


In creating techniques and contemplating the hypothesis that underlies the strategies analysts draw on an assortment of numerical and computational instruments. 


There is a lot to understand about Statistics, so are you ready to learn something new about statistics?


Several reasons will clarify why we need to study statistics such as it helps in conducting research effectively, any researcher needs to know what statistics they need to use before they amass the information and many such reasons.


This blog covers


  1. Definition of statistics
  2. Types of statistics,
  3. Applications of statistics,
  4. Variance in statistics,
  5. Advantages and disadvantages of variance in statistics,
  6. What is Bayesian statistics?


Definition of Statistics


In simple words, we can say that any raw data, when collected and organized in the form of numerical or tables is known as Statistics. Moreover;


  • It makes a set of data more easily understandable.
  • It is a branch of mathematics that analyses data and then uses it to solve different types of problems related to the data.


However, many people think of statistics to be a mathematical science. Statistics helps to read and understand the data in a very easy way. 


Consider a real-life example of statistics. To learn the mean of the marks obtained by each student in the class whose strength is 60, so the average value is the statistics of the marks obtained.


Now, presume you want to find out how many fellows are employed in a town. Before the town is settled with 10 lakh people, thus we will take an analysis here for 1000 people that is a sample, and based on that, we will build the data, which is the statistic.


There are two basic thoughts in the field of statistics that are uncertainty and variation. There are numerous circumstances that we experience in science or all the more for the most part throughout everyday life wherein the result is uncertain.


Sometimes, the uncertainty is because the result referred to isn't resolved at this point while in different cases the uncertainty is because even though the result has been resolved as of now we don't know about it. 


(Related article: Introduction to Statistical Data Analysis)


There are several applications of statistics like applied statistics, theoretical statistics, mathematical statistics, machine learning and data mining, statistical computing, and statistics applied to mathematics or the arts.


Some places from where you can find correct statistics are Statista, Nation Master, Google Public Data, Gallup, DataMarket, Dyytum, Gapminder, Freebase, SciVerse, and many more.


“The number of people who think they understand statistics dangerously dwarfs those who do, and maths can cause fundamental problems when badly used.”- Rory Sutherland


Types of Statistics


Now after understanding the definition of statistics let’s move towards types of statistics. We can say that statistics make our work easier and also helps in providing a better picture of the work we do in our daily life.


(Suggested read: Types of data in statistics)


So, two types of statistics are Descriptive Statistics and Inferential statistics. 


  1. Descriptive Statistics


In descriptive statistics, the information is summed up through the given perceptions. The summarization is one from an example of the populace utilizing boundaries, for example, the mean or standard deviation. Thus, it gives a graphical synopsis of information and it is just used for summing up objects, and so on. 


Descriptive statistics are applied to the data which is already known. It is an approach to coordinate, speak to and depict an assortment of information using tables, diagrams, and synopsis measures.


For instance, the collection of individuals in a city using the web or using television. In simple words, we can say that it is a modest way to clarify our data.


There are two categories under descriptive statistics-


  • The Measure of Central Tendency


There is another name for the measure of central tendency that is summary statistics. It is used to indicate the midst point or specific importance of a sample set or data set. Also, there are three popular measures of central tendency.


  1. The first one is mean, which is a measure of the average of all values in a sample set.
  2. Second is the median, where the data set is decreed from lowest to highest value and after that finds the actual middle.
  3. The third one is the mode, it is the value repeated maximum of the time in the central set is what we call mode.


(Recommended Read: Types of Statistical Analysis)


  • The Measure of Variability


There is another name for the measure of variability that is the measure of dispersion. It is used to portray variability in a sample or population. Also, there are three popular measures of variability.


  1. The first one is a range, which in simple language means maximum value minus minimum value.
  2. The second is variance, which clearly illustrates how much a spontaneous variable is different from the anticipated value.
  3. The third one is dispersion, which is a measure of the dispersion of a set of data from its mean.

  • mean.

The image is displaying the flowchart that depicts the types of statistics, i.e., Descriptive Statistics (divided into Measure of Central Tendency) and Inferential Statistics,

Types of Statistics: Descriptive and Inferential Statistics

  1. Inferential Statistics


In inferential statistics, predictions are made by taking any gathering of information in which you are intrigued. It tends to be characterized as an irregular example of information taken from a population to depict and make derivation about the population.


Any gathering of information which incorporates all the information you are intrigued by is known as population. Basically, it permits you to make expectations by taking a little example as opposed to chipping away at the entire population.


Accordingly, in simple words, we can say that it is a type of statistics used to clarify the significance of Descriptive statistics. That implies once the information has been gathered, dissected, and summed up then we use these details to portray the importance of the gathered information.


There are several types of inferential statistics that are used widely and are extremely simple to interpret. They are One-sample test of difference/One sample hypothesis test, Contingency Tables and Chi-Square Statistic, T-test or Anova, Bi-variate Regression, Confidence Interval, and more.


(Also read: Statistical Data Analysis Techniques)


Variance in Statistics


Variance in statistics is an estimation of the spread between numbers in a data set. That is, it quantifies how far each number in the set is from the mean and along these lines from each other number in the set. 


Variance is determined by taking the contrasts between each number in the data set and the mean, at that point squaring the distinctions to make them sure, lastly partitioning the amount of the squares by the number of qualities in the data set.


It is one of the critical boundaries in resource allotment, alongside connection. Computing the change of resource returns causes speculators to grow better portfolios by advancing the return-instability compromise in every one of their ventures.


Advantages and Disadvantages of Variance


  • Analysts use variance to perceive how individual numbers identify with one another inside a data set, instead of utilizing more extensive numerical procedures, for example, organizing numbers into quartiles.

  • It treats all deviations from the mean similar regardless of their path.

  • The squared deviations can't be whole to zero and give the presence of no variability at all in the information.


The disadvantages of Variance are;


  • Variance is that it gives added weight to exceptions, the numbers that are a long way from the mean. Figuring out these numbers can slant the data.

  • It isn't easily deciphered. Users of variance regularly use it principally to take the square root of its worth, which demonstrates the standard deviation of the data set.


What is Bayesian statistics?


Nowadays, the term 'Bayesian statistics' gets thrown around a lot. Also,


  • It is used everywhere like in social circumstances, games, and ordinary life with baseball, weather predictions and forecast, presidential election polls, and several more.
  • It is used in most logical fields to decide the consequences of an investigation, regardless of whether that be molecule material science or medication viability.
  • It is used in machine learning and artificial intelligence to anticipate what report you need to see or a Netflix show to watch.


Bayesian statistics is a specific way to deal with applying the probability of statistical issues. It gives us numerical apparatuses to refresh our convictions about random events considering seeing new information or proof about those functions.


Specifically, Bayesian inference deciphers probability as a proportion of believability or certainty that an individual may have about the occurrence of a specific function. Even more,


  • Bayesian statistics gives us strong numerical methods for joining our earlier convictions, and proof, to create new back convictions.
  • Bayesian statistics furnish us with numerical devices to reasonably refreshing our emotional convictions considering new information or proof.


(Also read: Statistics for Data Science)





In conclusion, we can say that statistics is important as you must have noticed that writers usually add statistics to make their point more valuable and stronger. It performs the task completely and provides an understandable resemblance of the task we perform regularly. 


The statistical techniques help us to inspect various regions, for example, medication, business, financial aspects, sociology, and many more.


(Check also: Crush Course for Statistics)


It furnishes us with various types of coordinated information with the assistance of charts, tables, outlines, and diagrams.


Hope so, this detailed discussion on statistics will help you in understanding better and clear your doubts about statistics.