Data science is a dynamic field that's not just expanding but constantly transforming in exciting new ways. This field not only plays a crucial role for businesses but also is pertinent for the growth and advancement of technology. In data science, statistical methods are essential for transforming raw, unreadable data into actionable insights.
It might come as a surprise but did you know that statistical methods and concepts play a very important role? They not only serve as a foundation but also as a tool to understand the relationships and trends within a dataset and this is what helps data scientists to obtain information that is complex but also meaningful to help their companies make informed and insightful strategies and decisions. Descriptive statistics summarise and describe the main features of a dataset, including measures like mean, median, mode, variance, and standard deviation. These metrics provide a snapshot of the data, making it easier for practitioners to interpret and communicate findings. In contrast, inferential statistics equips data scientists with the tools to predict outcomes and uncover insights about a population by analysing sample data. Concepts such as sampling distributions, confidence intervals, and p-values are integral to inferential analysis.In order to be successful in the field of data science you must be able to firmly grasp statistical methods and concepts and these are what will help you to learn data science and become an expert.
What You Need to Know About Probability?
Mathematics is something that is closely linked to data science and one of the most used branches of mathematics used is probability. Probability is basically the chances of an event occurring in a situation and it quantifies how likely that event is to occur. The chances of something occurring in probability are usually expressed in numbers between 0 and 1 whereby 0 is usually denoted by impossibility and 1 denotes certainty.
In order to calculate probability, you will need to divide the number of favourable events by the number of possible events. Simply put, P(A) = f/N
One good example that we can see how probability works is flipping a coin. A coin has two sides and therefore there are two possible outcomes which are heads of tails. The chances of getting heads is P(A) = ½ which is 0.5 or 50%

It might come as a surprise but probability is something that is used in a lot of industries such as medicine, finance and many more. Therefore understanding it is highly important especially if you are looking at getting into computer science.
How to Choose the Right Statistical Test for Your Data?
As you know when it comes to data science, conducting statistical tests is important but as someone who has just started their journey in data science, it must be difficult to determine how to choose a statistical test.
There are many types of statistical tests out there and we discuss a few of them later in this article but let us look at how you can determine which statistical test you should use.
The first factor you should consider is what is your research question or hypothesis that you are looking at. Is it something that is about variables? Or are you comparing means or proportions? Your initial question is something that will lay out the foundation of what test you will be using.
The second factor you should look at is the data type. Nominal, ordinal, interval and ratio are the four main data types. You will not only need to know the data type but also understand it in order to choose the correct statistical test.
Next, you will need to determine the number of groups and check the assumptions of the test. Sample size also plays a big part and this is where the use of software comes into play.
Always remember these steps as they lay out the foundation for how to choose the correct statistical test.
Understanding Tests of Association: When Are They Applicable?
When it comes to the world of data science, one of the important tools to understand relationships between data and variables is to employ tests that can statistically associate one of two variables together. This provides valuable insights that can help decision-making.
Test of association is important when you want to explore the distribution of one variable depending on the levels of another.
One good example of this is when a data scientist wants to see if smoking is associated with lung disease. This is where the test of association comes in handy. This test is commonly used especially in the field of medicine and research.
It might come as a surprise to you but this test of association is also widely used to understand and assess the behaviour of consumers. With this test, you can find out more about purchasing patterns based on demographics such as age, income levels and many more. This is highly useful for organisations especially to plan their strategies effectively.
This test is undeniably very important when it comes to linking and exploring the relationships between variables and it provides data scientist valuable insights that will help them with their analysis which in turn will result in making better and more informed decisions.
Overview of Test of Comparisons Between Means
Another statistical test that is important when it comes to data science is the test of comparisons between means. This is a method whereby to determine if there are significant differences between two groups or more. This is very important especially in data science because of hypothesis testing.
Some examples of comparisons between means are the t-test and the analysis of variance. The main difference between these two is the t-test looks at two groups meanwhile the analysis of variance is more suitable if there are two or more groups.
One of the assumptions of these tests is usually homogeneity. This implies the scores are generally the same.
On top of these, a data scientist also uses Python to perform tests that help them to draw insights from their data which in turn will optimise their marketing strategies.
When you understand these methods, you will be able to apply them effectively and correctly and this in turn will enable data scientists to make informed decisions obtained from their data.
How to Use Linear Regression for Predictive Analysis?
Another statistical technique that is important in the field of data science is linear regression. This technique is very important when you want to predict continuous outcomes and establish a relationship between variables.
Generally, there are several steps that are required when it comes to testing using this statistical method. The first is collecting data and processing them thoroughly by ensuring there are no outliers. The next step is to split the data into training and testing and then assess the performance. The final step is to use the train model to make predictions of the data which will allow insights and informed decision making.
It might sound complicated, but in the world of data science and even statistics, the linear regression method is known to be simple. One of the main uses for this test is to help with forecasting.

The reason why this method is commonly used in data science is because it is highly useful when it comes to identifying as well as predicting patterns.
What is the Test of Nonparametric Data?
Another statistical method that is used widely in data science is nonparametric data. This test is useful when it comes to a smaller population of data or when the data tends to be skewed.
You might be wondering when you will be using nonparametric tests when you deal with data. Here we have listed some of the reasons to use this kind of test.
- When the sample size is small
- Ordinal data - this is when numbers are not used in the data. For example, when rankings are used such as ‘satisfied’. ‘neutral’ and ‘dissatisfied’
- When data is skewed
Here are some of the common non-parametric tests used by data scientists:
- Mann - Whitney U test
- Wilcoxon Signed-Rank Test
- Kruskal-Wallis Test
Generally, the test of non-parametric data tends to be flexible which in turn makes it very valuable when it comes to data analysis and data science. They provide scientists the freedom to analyse data without the hassle of having stringent and set assumptions. This is one of the many reasons why this test is very useful when it comes to real-world applications.
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