Tag Archives: data analysis

A very interesting student work from my business statistics class

This is a very interesting presentation as the final exam of my “Business statistics” class at Yokohama National University in Japan.


My classes are all for international students and this is work of a student from Vietnam.

The students learned how to set a practical goal and how to effectively use some analytical techniques to support the conclusion(s).

The student tried to find out the difference of the students from two different countries, Vietnam and Japanese in terms of GPA and objectives to learn at university.


While the sample size is small and the conclusions are not necessarily surprising, the approach and analysis itself was quite interesting.


My class is not just to teach some academic analytical techniques but to teach how to apply those techniques to meet practical goals.

I would be happy to give my lecture anywhere in the world.


Hana 1Hana 2Hana 3Hana 4Hana 5


What you need to consider when drilling down the data.(vol.3)

The last factor to consider when drilling down the data is “data availability“.

It seems so natural to care about its availability but it is extremely important and practical to think of it before studying what axis you apply for the drill-down.

You may be able to consider any ideal axis to break the data but you may end up with giving up the idea during the analysis. In reality you cannot obtain all the data you need, especially if you are not an analyst or do not belong to such specialized organization for analysis who can afford to procure the data from outside, you have to manage/struggle to reach required outputs only with already existing (i.e. available) data at hand.

Before you notice the fact such data does not exist at hand at the end of the analysis, you should consider whether you have the data available to apply for the axis you choose.

My suggestions at my lecture and trainings are always very practical as above. They will help you save your time and efforts when you analyze business data.

Data analysis training for a public sector

I had a training program for one of the public sectors in Japan yesterday.

The mayor of the city has a tremendous sense of crisis on the current and future management of the city. He is eager to engage in the human skill development to improve the value and quality of the service and management.

The mayor directly asked me to support his initiative to develop the skills in the organization and it was the first step to have a basic training session.

As it was the initial session, I focused only on the very fundamental but essential topics such as:

– How to define an issue and develop hypothesis for the issue

– How to utilize basic analytical tools to describe the whole picture of the issue and identify the potential issue point(s)

I will continue my support in order for them to acquire those skills/proficiency in the organization.

I am so excited to be involved in such critical initiative and happy to contribute to the enhancement of the people.

Link to my website (in Japanese)  => http://data-story.net

Next semester at Yokohama National University

While it is in the spring break now, I would like to resume updating when the new semester starts in April.

I will have a class of “Logical problem-solving” for the international students, where I will talk about how you can solve business issues in a logical way to reach an agreement and/or to get an approval of a decision-maker.

Logical thinking approach is required for problem-solving and data analysis which can be a method for the problem-solving as well.
What I found at my class of the university or in the training programs for corporate clients was they need to learn more about how to apply the data analysis techniques for their practical problems.

They all depends on my personal and professional experience at the global company, Nissan Motor Ltd., where I used to work as a business/management problem-solver with its executives.

I am so excited to start the new program for the class and for my corporate clients as well.


Final session of “Modeling with statistics” class

It was the last session of my class today at Yokohama National University.

The final exam report was announced with the following requirements:


It was extremely wonderful experience to me and it was really fun!

My goal of this class has been how to solve real and practical issues in business, by developing a logical story with data (analysis).

I  the students enjoyed the class and will see them in the coming semester again for the class “Logical problem-solving”, in which I will talk about “Logical thinking to reach an agreement with stakeholders” !

I am so excited again. Please contact me if you need a lecture (one-day, short-term intensive or long-term) of decision science even outside of Japan.


From my lecture note at university #12(Modeling with statistics)

Today it was the second session for hypothetical testing.

We focused on testing a gap of two averages, which I believe is the most commonly used in practical business situations.

It was really hard to explain the concept of the statistical hypothesis testing, which is very confusing for beginners.

Concept of “Population” and “Sample” is the first one you have to understand as well as the fact that, in most cases, we are using “sample” data for data analysis.


From such academic topic, we moved to a practical topic, which is the test of two average gap between two groups.

Excel (T.TEST) function helps you to minimize your calculation to reach the conclusion as long as you understand how the testing works.


For the practical use, my advice was to focus only on the determinations on “one-tailed or two-tailed distribution” and “type of the testing”, which you have to specify in the function.


Once the class understood the concept and theory, we moved to the practical exercises.


Apart from those exercises, we tested the gap of average amounts to pay for lunch between “female” and ” male” students, by using sample data of the class.

It was really fun!

Finally this is today’s take-away.


Thank you again for enjoying my class today!

◾From my lecture note at university #11(Modeling with statistics)

We started inferential statistics today but only for this week and next week.

Many people hate the statistical testing staff as it is very confusing and sometimes they feel it not practical. Therefore, I focused only on the most practical one which is testing a gap between two averages using T-test.

It was really hard to explain the concept of the statistical testing (population and samples). At the start, I used an example of coin-tossing to test the 50%:50% chance.

Secondly, I reminded the students that the data we had been using was just sampled data not from the population, which you have to be aware of.



I always try to explain a practical way to use the statistics, rather than just a theory. The step chart below was used as an introduction.


This was the hardest part to explain. I showed two approaches, critical value approach (t-value) and probability approach(p-value).


Finally, as always and as my policy, I had the students to solve some practical problems as follows:


At the next session, we will continue to learn more about the statistical testing.