About the class

Hi, I'm Jordo and I'm currently working as a data scientist in my 7th year at a financial company.

I opened this class to share what data analysis I do in the business while working as a recommendation system developer in the past and currently as a data scientist.

When it comes to data analysis, you probably think it's a difficult field to challenge because it seems like a lot of students and PhDs.

However, data analysis in the business is not that complicated.

For example, how can we check whether the marketing implemented by the company was effective?

It's enough to divide customers who are not customers to implement marketing, collect data after implementation, and compare the effects that will be triggered by marketing by considering age groups and gender.

Do we need a lot of statistical knowledge to solve this problem?

The knowledge I used here is basic statistical knowledge such as 1) dividing the experimental group/control group 2) testing based on distribution.

In this way, many data analysis tasks solved by companies are confident that 95% or more of the problems are based on basic statistical knowledge.

Another 5% problem? You can ask the doctors and doctors to solve it.

The classes are structured so that basic statistical knowledge, efficient methodologies used in practice, and difficult words can be understood intuitively and used immediately.

Learn basic statistical knowledge and test various hypotheses based on this. Also, the fact that you can fully analyze a medical paper that seems difficult based on what you have learned is also covered in class.

Please be stubborn and use it in your business.

Course effects

• Beginners who don't know anything about data, people who don't know coding, and people who don't know statistics will be able to freely analyze data.

• You will learn about statistical ways of thinking.

• You will be able to speak with confidence by proving the hypotheses floating around in the company with data.

Recommended target

• Those who gave up on statistics classes because of difficult words such as null hypothesis, type 1 error, etc.

• Those who want to learn coding for data analysis but don't know where to start

• Those who want to do a good job at a company

Notes before taking the course

• This class uses Colab, an online code notebook. Anyone with a laptop can do it.

N reasons why this class is special

❶ Arithmetic mean? Geometric mean? What should I use?

Average, which is an indicator for identifying the characteristics of data

Can I use it any way I want? The arithmetic mean always has a value greater than the geometric mean in most cases.

If you use an indicator without knowing its characteristics, an overestimated average value will come out!

(EX: My profit rate is 500%!!! , 20% in practice)

❷ My math score is 50 points and my English score is 80, which subject did I do better?

Are they better at math because each subject has a different level of difficulty and a higher English score? Standardized variables used in this case

By using standardized variables, it is possible to make more accurate comparisons by considering the level of difficulty between subjects.

❸ What kind of marketing was most effective?

Did marketing really work? Which marketing was more effective?

We use variance analysis to measure the effects of marketing (= factors) that are thought to have an impact on sales (= experimental results).