## A Pratical Tip To Validate Your Approach

I have just enrolled in a Data Science course on Udemy  and I learned good stuff.

How was the A/B test « Number Of Product » ? Easy or difficult ?

Here is the result I found.

I think you noticed there was something bizarre. There is an anomaly. We imagine that the more the client has products, the more the client is satisfied with the bank so this type of clients should stay in the bank.

In the first 2 bars we can see that a client who has 1 product is more likely to leave the bank than a client who has 2 products. But when a client has 3 or 4 products, we see a huge rate of clients leaving the bank.

Look, there is a little bizarre detail. In the 2nd bar, we can’t see the « Exited » label. This is because there is no place in the orange part to put the text. To make it simpler, we’ll remove the label « Exited ». Drag and drop on the « Exited » text label to the outside.

Perfect, we can read the percentages. On the 1st bar, we can see that among the client that have 1 products, 28% left the bank. On the 2nd bar, we can see that among clients who have 2 products, 8% left the bank. This show us that clients who have 1 products are more likely to leave the bank than clients with 2 products.

And for the next bars, we observe an anomaly. On the 3rd bar, we can see that among the clients who have 3 products, 83% left the bank. On the 4th bar, we can see that among clients who have 4 products, 100% left the bank. We clearly see that there is a problem and we need to do a deeper analysis to understand what is going on .

As a Data Scientist, we need to explain what happens in bars 3 and 4. Usually when a client has 3 or 4 banking products, that means he/she is satisfied and is loyal to the bank. But in our case, it’s the opposite because there is a high rate of client who left the bank. This is the time to do deeper analysis.

The first thing to analyze is the quality of the data. There is a very big anomaly and it may be because there is something insignificant in our data that disturbs the statistics. For example, it’s possible that when the bank selected these clients in this sample, there were very few clients with 4 products and all those clients with 4 products left the bank. Sometimes chance can create anomalies and you have to play attention to these effects of chance because they don’t seem important but they can create false interpretations.

To start, we will check the number of clients with 4 products.

In « Measure », move « Number Of Records » (which gives the number of observations) on « Label ».

We observe on the first 2 bars than many clients with 1 or 2 products selected for our sample. For clients with 3 or 4 products, we can see that there were fewer clients selected for our sample.

There are 220 clients with 3 products and 60 clients with 4 products. These small number of clients probably explain why we observe these anomalies.

In this sample of randomly selected clients, there are very few clients with 4 products and they all left the bank. In this situation, we can confirm that it’s a chance. When thing like that happen, you have to be very careful not to make conclusion too fast and make misinterpretations.

The conclusion is that a lot of clients have been selected for category 1 and 2. For category 3 and 4, there have been few clients selected so we can’t do accurate statistics. We need to do deeper analyze for these categories of clients with 3 and 4 products.

Now, let’s put the percentage back on the bar chart. Click on the « Back » button.

.

Or do a click and drag of « SUM(Number of Record) » to outside.

We saw that there is an anomaly and what is interesting to do is to have a comment to remember to do a more in-depth analysis of columns 3 and 4.

Right-click between the bar chart’s title and the bars. Select « Annotate » then « Areas… ».

A window appears. In this window, you write « Low observation in last 2 categories » and click on the « OK » button.

Click on the comment and move it on bars 3 and 4.

The next time you work on this bar chart, you will see this comment that will remind you to seriously analyze client who have 3 and 4 products.

# Validate our approach

It’s time to show you how to validate an approach and how to validate the data. For this we will create a new A/B test.

Duplicate this worksheet with a right-click on the « NumberOfProducts » tab and select « Duplicate ».

And rename the tab « Validation ».

For this tab, we will erase the comment. Select the comment and press the « Delete » button on your keyboard.

Everything is ready, the idea is to find a variable that doesn’t affect our results. That is a variable that has no impact on a client’s decision to leave or stay in the bank.

Take for example, the variable « Customer Id ». Client’s identification number has no influence on the client’s decision to stay or leave the bank.

We’ll do an A/B test with the last digit of the « Customer Id » and we’ill check that there is the same clients proportion who leave the bank in the 10 categories of the last digit of the « Customer Id ». The 10 categories are the numbers 0,1,2,3,4,5,6,7,8,9.

Let’s g.To start, we will create the variable that contains the last digit of the « Customer Id ». To have this variable, we will create a « Calculated Field ».

Right-click on « Customer Id », select « Create » and click on « Calculated Field ».

Name the calculated field « LastDigitOfCustID ». In the text field, we use the « RIGHT » function with « Customer Id » in parenthesis to select the last character of the « Customer Id ». In our case, the last character of the « Customer Id » is the last digit.

Here is the code to write in the text field : Right ({Customer Id},1)

Oooops, you see there is a small mistake => The calculation contains errors.

There is an error in the formula because « Customer Id » is a number variable and the « RIGHT » function applies to a variable of type « STRING ».

To use the « RIGHT » function, we will convert « Customer Id » into a string. We will use the « STR » function with « Customer Id » in parenthesis.

Here is the code to write in the text field

And click on the « OK » button : Right (STR({Customer Id}),1).

Now, you can see that our calculated field « LastDigitOfCustID » is in « Dimensions ».

Click on « LastDigitOfCustID » and move it on top of « NumOfProducts » in « Columns ».

Now we have a new bar chart and we see that for every last digit of the « Customer Id » there is about the same proportion of clients leaving the bank. All these proportions don’t correspond exactly to the average of 20% but these slight variations aren’t important.

Seeing this uniform distribution allows us to validate our data because these data are homogenous.

# Conculsion

Here’s how you can check the homogeneity of your data. You take a variable that has no impact on the fact that a client leaves or stays in the bank. The example we did with the last digit of the « Customer Id » is excellent. We were able to verify that in each of the categories taken by this variable, if there was the same proportion of clients leaving the bank. As is the case, we can validate our data.

Imagine another result. When we do the test with the last digit of the « Customer Id », we observe that for one of the numbers, the rate of clients who left is really higher than the average. This shows us that there is a problem in our data because it indicates an anomaly.

You can find other ways to verify your data by using other « insignificant variables » to see if the distribution is homogeneous. But be careful when you select an « insignificant variable » because there may be traps.

Here is an example. If you create a variable that takes the first letter of the first name, the distribution will not be homogeneous. The reason is simple, there are many more people who have a name that starts with the letter « M » than with the letter « Y ».

-Steph

I watched an Olivier Roland’s video  and I learned good stuff.

Here are the benefits of creating content frequently.

# Share techniques

I like to share the techniques, tactics and methods that I tested and worked for me and for others. As an athlete, I like to see my potential’s extent, I like to win and I like to see people around me win. It’s always frustrating to see someone who has a talent and isn’t fighting to realize their dream.

Often when I discover something in a book or someone shows me a technique that I test and that works, I want to say to the world « Look this technique works, try it right now ». That’s why I created my blog.

# Challenges

I watched a The Family‘s video  (I wrote an article about it Part 1 , Part 2 and Part 3). I decided to publish 5 articles per week for several reasons :

As an athlete, I like to push my limits. Posting 5 articles per week has forced me to find themes that fascinate me so I can enjoy learning new things and writing articles about it. Every day, I’m looking for new things. There are articles I write and don’t published because I realize that it doesn’t fit my vision.

At the beginning of my blog, you can see that I write articles to introduce some bodybuilders and I stopped doing that because I decided not to talk about athletes using steroids. With challenges, it allows me to refine the vision of my blog and my failures are part of the learning process.

# Frequency

From, 2014 to 2015, I published 1-2 articles per week. Toward the end of 2015, I watched a video about a 30-day challenge. After watching this video, I decided to write 5 articles a week for 30 days and after published 1-2 articles a week. During the 30 day challenge, it was difficult for me to write articles (find subjects and find the time to write texts) but my blog’s traffic seriously increased. When I took the rhythm of 1-2 articles a week, I felt less stressed because I had less pressure but my blog’s traffic of my blog had decreased.

I started to get frustrated because one of the important things for a blog is to have traffic. So, I started again this challenge of 5 articles per week during 30 days by writing only on topics where I have fun. My blog’s traffic increased like the first time. Frankly, it’s cool because I know that with this frequency, I can reach more people. And that allows me to develop my business. Yes, it’s possible to bring value to the world by bringing value to yourself, thus making money. Both are compatible.

Today, I have prospects and clients coming from my blog. People read my articles, it’s free and then they send me emails or messages with social media to find out if I can solve one of their problem.

# Learn

With this frequency of publication, 5 articles per week, it allows me to accelerate my learning curve. You can see the difference of writing between my first articles and my last articles. I improved my writing style. All that, it took me a long time and I know that I have a lot of things to improve. And I also learned that success is something that builds little by little. There is no success in 3 months or 1 year. Success is a thing in the long run. You learn to make the difference between lies and truths to have a healthy life in all areas.

For 1-2 years, you can see I’m learning to make videos on Instagram and Snapchat. I make 5 videos a week. Since about 6 months, I make an audio file (podcast) on my old exercise articles. In this audio file, I read the article so that you can have the information in a passive way. You can listen to my audio file while driving, working instead of listening to music. Making videos and podcasts are things I learn to do for my blog.

# Have fun

Sharing content frequently no matter the format, text, audio, video, it’s something that I do with fun. People are asking me how do I keep doing this for years. The answer is that I have fun when I do that. It’s like when I train or dance Cuban salsa. When I do that, I have fun and if I can learn something to improve myself, I do it.

I know there are people who create content to make money quickly but it doesn’t happen that way. You need to do this for 3-5 years for free to build your reputation and then you can afford to make money. That’s why it’s important to have fun when you do that because the difficulties come, you see them from a different angle. There is no cheat code so have fun.

-Steph

## Be Limitless Like In The Movie

I read an Nerd Fitness article  and there is good stuff.

You’ve heard we use only 10 % of our brain. Do you imagine be able to use 100 % of your brain ?

The book and the movie « Limitless » are based on it and when I watched the movie, I liked it. A lot of people liked because we dream about it for years.

« Limitless » is the Eddie Mora’s story who by chance find pills that give a unlimited power to his brain. He write a book in 4 days, he leans several new langages, he stops smoking, he lose weight and gain muscle. He earns a lot of money in stock market.

This guy transformed his life in video game (he becomes a little bit like James Bond). Is it possible to become more productive without medications ?

# How

To become limitless, here is the list of things we should be able to do :

• Read more often – We can read a book very very quick and remember all the important things.

• Write a book – We can write a book in few days or weeks instead years.

• Learn a langage – We can talk a langage in few weeks and we can have a nice conversation with people with that langage is their native langage.

• Have an excellent physique – We can train in an effective way without spend several hours in the gym to see results.

Maybe you will change some things in this list but I think this list is fun.

The concept is to accomplish more things by spending less time :

• The ability to spend more time to learn

• Make the time you spend learning to be more effective

# First : Exercice

Here a excerpt from an article of Scott’s website « Live Your Legend »  :

While on a boat with Richard Branson, a man asked « How can I be more productive ? » Keep in mind, Richard is the founder and operator of a 400-company conglomerate. He also has dyslexia and a pretty piss poor academic track record.

Yet somehow, from space travel to deep sea exploration, to music and cell phones, this guy has literally been able to accomplish a bazillion times more than the average Joe. And he’s still only 61.

Hence, the crowd of boat passengers hung on the edge of their seat cushions in anticipation of what turned out to be an unbelievably simple answer…

Richard responded: « Work out ».

Charles Basch of Columbia University summarized how exercices affect functions :

• Increase oxygen flux to the brain

• Increase brain neurotransmitters

• Increase neurotrophins that ensure the survival of neurons in the areas responsible for learning, memory and higher thinking

Dr John Rathey who wrote « Spark: The Revolutionary New Science of Exercise and the Brain »

and « Driven to Distraction: The Study of Attention Deficit Hyper Disorder »

give many studies on physical activity and the increase of focus and the increase of the memorization when we study. « Exercices don’t make you more intelligent but they help to optimize the brain to learn ».

It’s with this study that  Charles Hillman discovered that do a few phyical exercices before school can increase memory of 5-10 % among children.

# Second : the plan

Malcolm Gladwell says in his book « Outliers »

that people become expert after 10 000 hours of pratice. Warning, you must learn in the good way, otherwise you become an expert by doing it with a bad execution.

It’s mean, if we learn something in the good way, 8 hours per day everydays, we should be an expert in 3 years and a half.

But we don’t have all this time and we don’t want to be the master of the experts.

When we learn a langage, a dance, a martial art or a new musical instrument, we need to identify the key movements or the key words. We need to become proficient in the skill. Don’t worry about the rest of the stuff.

Exemple :

A new instrument

Rather than studying complex compositions of classical music, look current music and studies the patterns.

• If you learn basic guitar chords, you can learn 80 % of popular music.

• If you learn basic piano chords, you can quickly learn pop music you always wanted to play.

The goal isn’t to to play in a symphonic orchestra but to learn the basics and take pleasure in making progress.

Look this book « The Talent Code »

# Third : Environment

Now our brains are ready to learn and we identified the skills or goals we want to have, it’s the time to create an environment for success.

I wrote an article to create your headquarter . We will do the same thing to help us to become limitless.

A : Stop to being multitasking

Often people advise to be able to do several thing in the same time but the only thing this behavior do is to decrease your ability to learn and your productivity. Look the results you have when you work and every 10 minutes you watch a video on YouTube. Every time you change activity before you finish, you become less creative and productive.

Si you want be productive, focus on one thing and finish it. If you learn a new langage, dedicate time only for it and nothing else.

B : Remove all distractions

Often people thing they can do their passion in evening around 21h-22h (9pm-10pm). It’s not true because people are distracted very easy all day. They spend a lot of time on Facebook, Youtube, Gmail, Instagram, Snapchat, etc. Then when everybody sleep, it’s at this moment they work on their passion.

Work on your passion immediately after your school/work and you will see the difference. It’s guarantee !

There are apps like « Self Control »  to allow you to not be distract any more

If you want write a book, go in a boring place. Don’t go in a place where there is a lot of cool stuff.

If you want read a book, go in a place where there isn’t TV. Don’t be tempted or cancel you cable (we can watch everything on internet now).

# Be Limitless

Here principles :

Exercice. In the morning 10 minutes of bodyweight’s exercice

Plan. You know exactly the 2 skills you need to study and they must be done before 16h (4pm).

Environment. Blocks for a certain time websites that can disctract you. Cancel your cable also.

# Hack

Everydays

James Clear’s tip . If you learn a musical instrument or a langage, do it for 5 minutes each day. Create this habit is more important than the « perfect » time.

Use help of others

If you want learn something quickly, you can find some people who learned this skill quickly. Ask to this person how he/she learned this and test it.

Make mistakes the 1st day

You can learn a langage with a grammar book for years but if you don’t speak this langage with people, it’s useless. It’s like deadlift or something else, accepts that failure is a part of the process to be better.

Learn 1-2 new skills

Learn Taekwondo, piano and spanish is too much. Select 1-2 and stay focus on it.

Different kind of music

If you try to read more or be more productive at work, experiment different type of music like rap, electro, classical music, movie soundtrack, etc. At different moment of the day, you need to be in a different state of mind (calm, aggressive), use music to be more productive.

Sleep more

In the movie « Limitless », Eddie Mora lives with the minimal hours of sleep every day. In the reality, it isn’t possible to sleep 4h. A body lacking sleep functions similarly to an intoxicated body  .

What skill or goal you want reach ?

-Steph