Break For Injuries

sport injury

What’s up ? This is THE stephane ANDRE and today I didn’t train. I will tell you why, because I feel pain to my left shoulder and my 2 knees. 6 day ago, it was my leg day and you know, I hurt my right knee during a martial art session. So I used lightweight to train my leg.

Since around 6 months, I felt pain to my shoulder (shoulder impingement) because of the dumbbell overhead shoulder press and dumbbell bench press. Since 1 months, I hurt my right knee in a martial art sparring, because I wanted to avoid a punch and my leg (my knee) was in a bad position. I had 2 injuries . I searched an alternative exercise for the dumbbell overhead shoulder press and dumbbell bench press to decrease the pain and I found out. I wrote 2 articles about it. Click here and there .

Too much injuries

sport injury

As it was a leg day, I decided to do front squat with lightweight to not hurt to much my right knee. After my front squat session, I did leg press with one leg. After my warm-up set, I felt a pain in my left knee, it was like if someone hit my left knee with a knife, I stopped my rep immediately. It was the first time I felt this pain and I didn’t like it. I tried to do an another rep to see the gravity of the pain and I stopped my leg day here.

I did the half of my leg day’s program and I thought it was a good idea to test the new way to do dumbbell bench press without pain. When I was walking with the dumbbell in my hands, I felt the pain in my left knee. I did this dumbbell bench press variant and I validate it.

Usually after my workout, I eat my meal (my post workout is solid food). While I was eating my meal, I thought it was the time to make a break. 3 injuries is too much for me and I decided quickly to make a break of 1 month to really recover, because since 2015 I train regularly 6-7 days per weeks and the longest break I make was 10 days. Yeah, 10 days. When I realized it, I thank God of Light for his gratitude. And you know what ? When I slept, I felt I a little pain in the middle of my back. It means to do my front squat, my body compensated the weakness of my right knee with others parts of my body to be able to execute the movement.

Special recovery

Now, it’s the 6th days and I continue to write article for my blog and I learned what kind of injuries I have and I want to learn deeper about sport injuries because I scare to become like Ronnie Coleman. Ronnie Coleman is the best bodybuilder for me, it’s because of him I started seriously to train like a bodybuilder when I was on the streets. And now, see this living legend who can’t walk without a crutch, it’s too sad.

I want to have the best athletic body I can until I die, I’m more focus about sport injuries. More I know about it and more I can avoid it. Every day I do my stretching session and I do 2 special movements to help my left shoulder to decrease the pain. I will see on 15th July, if my recovery session is effective.

It’s important not to take lightly the pain of your body. I know a lot of people who had pains a few years ago and they had to do some surgery. Now, they can’t use their capacity at 100%.

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-Steph

Ankle Sprain

ankle sprain inversion lateral

What’s up ? This is THE stephane ANDRE. With my training, I’m interested in biomechanics to avoid injuries. I read « Sport Medicine Media Guide » and I learned some good stuff.

A sprain is a stretch injury of the ligament that supports the ankle. This sprain often happens to the ligament outside the ankle when the foot is twisted inward (inverted). It’s a « lateral » ankle sprain that localized to the ligaments in the outer/lower part of the ankle.

A « high » ankle sprain (or syndesmosis injury) is a ligament stretch injury that holds the tibia and fibula together in the lower leg. This type of sprain happens when the ankle is twisted outward, it’s an eversion injury.

ankle sprain inversion eversion syndesmatic lateral medial high

When there is a sprain, the ankle is tender and swollen on the outside, above and at the front of the ankle bone, but the pain doesn’t come from the ankle bone. A sprain can create moderate or severe pain that can prevent the foot from supporting the body weight.

ankle sprain stretch injury grade

Treatment of sprained ankle

ankle sprain rice rest ice compression elevation

The basic treatment is what we call RICE (rest, ice, compression and elevation). During a severe sprain, it’s advisable to use a walking boot to help support the ankle.

Recovery time for a « lateral » sprain is usually 1-3 weeks and for a « high » sprain is usually 3-6 weeks.

Rheabilitation can begin a few days after the sprain when swelling decreases. The rheabilitation has 3 goals :

  1. Restore movement et flexibility

  2. Restore strength

  3. Restore balance

How to avoid a ankle sprain

It’s possible to use a brace to help prevent sprains. There are several types of neoprene or elastic materials. Here are some models on Amazon, click here .

Statistics

  • Ankle sprains are more commun in all sport that involve cutting and pivoting

Subscribe to my newsletter and share this article if you think it can help someone you know. Thank you.

-Steph

Chi-Square Test With More Than 2 Categories

tableau chi square test

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

In this article, we will do a Chi-square test with more than 2 categories. We will use the A/B test « Country » which has 3 categories which corresponds to 3 countries : German, Spain and France. Select « Gender Actual » tab, make a copy with a right-click and select « Duplicate ».

tableau chi square test

Name the tab « Gender Actual (2) » by « Country Actual ».

tableau chi square test

In « Dimensions », move the variable « Geography » over « Gender » in « Columns » to replace « Gender » with « Geography ».

tableau chi square test

tableau chi square test

Here’s how to do an A/B statistical test when there are 3 categories. We’ll start with the classic method and then I’ll show you another way to do Chi-square test with any number of categories.

Let’s start with the classical method. In this case, there are 3 categories so we can’t use the online tool of the previous article. In the previous article we used an online tool with only 2 categories « Sample1 » and « Sample2 ». That’s why we’re going to use another online tool, click here  .

tableau chi square test

In this online tool, we can enter the values without using the total values. That is, we enter only the number of observations in each category. We simply need to enter the values that are on our A/B test. And I’m going to show you how to turn our A/B test into a table. In this way, it will be easier to enter the values in the online tool without making any mistakes.

Go to the « Show me » tool at the top right.

tableau chi square test

Click on « text tables »

tableau chi square test

tableau chi square test

Click on « Swap Rows ans Columns » button.

tableau chi square test

tableau chi square test

Cool, now you have a table arranged in exactly the same way as the online tool.

In the online tool, we will select 2 rows and 3 columns.

tableau chi square test

As we have 3 categories and 2 possible results, we enter our values exactly as in the table we just created on Tableau.

tableau chi square test

Perfect, our table is ready. You can click on the « Calculate » button.

tableau chi square test

tableau chi square test

As you can see, we observe the same thing as the other online tool. There is our indicator « p » value which is less than 5%. Which means there is a meaning.

tableau chi square test

This statistical significance means that these results are valid for the total number of the bank’s clients and not just for the sample of 10 000 clients. We observe similar differences with A/B test « Country » whose results are based solely on the sample of 10 000 clients. We can conclude that in the total number of the bank’s clients, it’s the clients in Germany who are more likely to leave the bank. This is how we do things cleanly.

You saw, this online tool limited by 5 by 5 tables so you can’t use this tool when you have 6 categories or more. But fortunately it’s possible to do Chi-square test with any number of categories. It’s a special method and for you to understand that, I’ll give you a theoretical explanation.

Here we have 3 countries : German, Spain and France.

tableau chi square test

What we’re trying to compare is the clients number leaving the bank in each of these countries.

tableau chi square test

With our basic A/B test based on a sample of 10 000 clients, we obtained 16% for France, 32% for Germany and 17% for Spain. Now the question is : « Do we observe the same results on the total clients number of the bank ? », it means : « In general, does the country have a significant effect on the clients number leaving bank ? ». Germany has the largest number of clients leaving the bank so the idea is : « Why would we need to compare the 3 countries at the same time ? ».

tableau chi square test

If we do an A/B test statistical test with Germany and France and we get a significant difference in the clients number leaving the bank between these 2 countries, then that would mean that in general, the country has a significant effect on the clients number who bank. Indeed, if we find by comparing Germany and France that the Germans are more likely to leave the bank than the French, we can consider that Spain will not change anything. Germans will always be more likely to leave the bank than the French. Maybe there will be a different relationship between Germany and Spain but there will always be a statistically significant difference between France and Germany with a larger number of clients leaving the bank in Germany than France.

Here is a way to confirm that this logic is true. There is a test and the participants of this test are German, Spanish and French. Imagine that this test was done without looking at what is happening in Spain. Now you get the result and you ask yourself the question : « Would the results changed if you added Spain ? ». The answer is « no » because there is no interdependence between Germany, Spain and France. That is, the decision to leave the bank in France and Germany doesn’t depend on Spain. And therefore, it’s quite correct to separate the categories by putting 1 aside to compare the 2 others. And as now we have 2 categories, we can do a Chi-square test with the online tool that we used in the previous article.

So let’s go back to our worksheet and put a country aside to compare only 2 countries. Select « Country » tab.

tableau chi square test

What we observe is that the difference between Spain and France is very small, so it wouldn’t be interesting to do a Chi-square test between Spain and France. It’s more interesting to do a Chi-square test between Germany and France and to prove that there is a statistically significant difference between these 2 countries. This will be enough to conclude that the country has a statistically significant impact on the clients number who leave the bank.

Selects « Country Actual » tab.

tableau chi square test

We will use the online tool of the previous article, click here  .

We will make a copy of « Country Actual » to have a bar chart with absolute values. Select « Country Actual », right-click and select « Duplicate ».

tableau chi square test

In « Show Me », select « horizontal bars ».

tableau chi square test

tableau chi square test

Removes « SUM (Number of Records )» from « Columns » and removes « Exited » and « Geography » from « Rows ».

tableau chi square test

tableau chi square test

In « Dimensions », move « Geography » in « Columns ».

tableau chi square test

tableau chi square test

In « Measures », move « Number of Records » to « Rows ».

tableau chi square test

tableau chi square test

In « Measures », move « SUM(Number of Records) » in « Label ».

tableau chi square test

tableau chi square test

In « Dimensions », move « Exited » in « Label ».

tableau chi square test

tableau chi square test

In « Dimensions », move « Exited » in « Colors ».

tableau chi square test

tableau chi square test

We also need total absolute values, which means the total number of men and women. There is a very fast way to get that. Right-click on the vertical axis and select « Add Reference Line ».

tableau chi square test

Then in « Value », click on the drop-down on the right and select « Sum » to have the total sum of the observations.

tableau chi square test

And in « Scope », you select « Per Cell » option to specify that you want the total sums for each category, male and female.

tableau chi square test

Now, we have the total sum at the top of the bars. We will modify labels to have the absolute values. In « Label », we will change « Computation » to « Value » and click on the « OK » button.

tableau chi square test

tableau chi square test

tableau chi square test

Here’s how to enter the data :

For « Sample1 » in #success, you enter 810 because there are 810 people who left the bank. For « Sample1 » in #trials, you enter 5014 because there are 5014 people in total.

For « Sample2 » in #success, you enter 814 because there are 814 people who left the bank. For « Sample2 » in #trials, you enter 2509 because there are 2509 people in total.

tableau chi square test

Here is the verdict : « Sample2 is more successful ». « Sample2 » corresponds to German’s clients and #success is :« yes, the client left the bank ». This verdict means that of all the clients from German are more likely to leave the bank than clients from France. And look, there is something important, it’s « p<0.001 ». This means that the « p » is strictly less than 0.001. As you can see, « p » value is very small, which concludes that the tests are statistically significant.

Ooh, there’s another thing I wanted to show you with the tab « age » with the 2 bar charts in parallel.

tableau chi square test

As you can see, there are many categories (more than 5) because each category corresponds to a 5-year ago group with clients of the bank aged from 15 to 90 years old. This is a lot of comparison but it would be a good exercise for you to find what are the 2 categories to compare that shows that there is a significant statistic difference.

I give you a hint, compare slices from 50 to 54 years old or from 35 to 39 years olds. In fact, you should compare all peer categories where you observe difference on this basic A/B test. Do a basic A/B test with absolutes values. Then do a Chi-square test to check if the difference is statistically significant, I mean, if the result is valid for the total number of bank’s clients.

This is a way to statistically validate the insights we see onTableau. You see, it’s not very difficult and it’s effective. Here is a way to find insights on Tableau and validate them.

Subscribe to my newsletter and share this article if you think it can help someone you know. Thank you.

-Steph

Anterior Cruciate Ligament Injuries

anterior cruciate ligament injury tear

What’s up ? This is THE stephane ANDRE. With my training, I’m interested in biomechanics to avoid injuries. I read « Sport Medicine Media Guide » and I learned some good stuff.

Knee is the largest and most complex joint of the body. There are 4 primary ligaments (with their muscles and tendons) and secondary ligaments for the knee to function properly. Here are the ligaments of the knee : there are 2 ligaments on the side the medial collateral ligament (MCL) and the lateral collateral ligament (LCL) and two crossed ligaments in the center of the knee, the anterior cruciate ligament (ACL) and the posterior cruciate ligament (PCL).

Anterior cruciate ligament connects the front top part of the shine bone to the back bottom part of the thigh bone and keeps the shin bone from sliding forward.

anterior cruciate ligament

Injury

anterior cruciate ligament injury tear

There are several ways to have an injury to the anterior cruciate ligament :

  • The injury can be done because of a direct hit on the knee, which often happens in team sport.

  • The injury can be done without contact with an object in a situation where the knee forced to be in a abnormal position, which causes a tear in one or more ligaments of the knee. Or when an athlete in the race change direction. Or when an athlete make a hyperextend of the knee when landing a jump, which often happends in agility sports.

Diagnostic

In the majority of cases, the doctor is able to identify what is the injured ligament. But the knee can also be injured at the joint on the surface and in this situation, it’s more difficult to diagnose because of knee swelling. To make an accurate diagnosis, it will be necessary to use a MRI scan or arthroscopy.

Prevent

There are several fast, powerful movements that lengthen (eccentric phase) and shorten (concentric phase) a muscle. These prevention programs are for injuries without contact. These exercises are to improve the nerves/muscle control of the knee. These prevention programs use plymetrics, balance and strength/stability exercises.

Plymetrics

It’s a fast, powerful movement that lengthens (eccentric phase) and shortens (concentric phase) a muscle. The concentric phase increases the muscle power. Here is an example, an athlete who jumps from a box and immediately jumps into the air after touching the floor.

Balance

Balance exercices are done with the wobble or balance board. It’s also possible to perfom exercices by throwing a ball with a partner while balancing on one leg.

Strength/stability

To improve single-leg core strength and stability, there are excellent exercices such as jumping and landing on one leg with the knee flexed and momentarily maintaining this position.

Surgical treatment

In the past, there was a technique that consisted of stitching the ligament together but it was rarely successful. Currently, the technique involves reconstructing the anterior cruciate ligament by building a new ligament from tissue taken from one of the other tendons around the knee or from on organ donation. This tissue passed through drill holes in the thigh bone and the shin bone, and then ancored in place to create a new anterior cruciate ligament. Over time, this transplant becomes mature and becomes a new living ligament in your knee.

Recovery

recovery

Rheabilitation of the knee after the reconstruction of the anterior cruciate ligament requires time and work. To have a complete function, this can last between 6 weeks and 6 months depending on the severity and level of activity. Rehabilitation rate may take time depending on the specific requirements of the sport/physical activity of the individual.

The overall success rate of the anterior cruciate ligament surgery is very good. A lot of study show that more than 90% of patients are able to return to sport without symptoms of knee instability. It’s true that some patients complain of stiffness and pain after surgery, that is why it’s necessary to make an aggressive rehabilitation until the new surgical technique to reduce these problems.

Statistics

  • One of the most commonly injured ligament in the knee

  • Female athletes participating in basketball and soccer are 2-8 times more likely to suffer anterior cruciate ligament injury.

  • Athlete who suffer anterior cruciate ligament injury at increased risk of arthritis development later in life.

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-Steph

Feed Your Brain Is Important

feed brain

What’s up ? This is THE stephane ANDRE. I watched an Olivier Roland’s video  and I learned some good stuff.

To be successful in the areas that interest you, there is an important principle that is to nourish your brain in a healthy way. It’s the same principle for your body. If you eat fast food burgers every day, you’ll become fat, your self- esteem will decrease, your energy will decrease, your libido will decrease and your lifetime will decrease.

If you feed your brain every day with the « burgers » of information, I mean news (newspaper and tv), you’ll have a negative state of mind. The information of these newspapers or these media are 95% negative and 80% of this information, you’ll forget them in 15 days. These are events where you have no impact on it, it uses your brain’s energy for noting and because of this negative information, you become more and more worried.

Good food for the brain

The most efficient and accessible way is to read books of excellent quality. When you read books of excellent quality, you have access to the best brains in the world for an affordable price, or even free if you go to a library. With books, you also have access to the best dead brains. It’s not because the person is dead that this person has to stop giving us value.

Purpose of reading these books is to allow you to have a solid foundation for achieving your goals. To start, you need to create a list of books and use the SMART goal method (SMART => specific, measurable, accessible, realistic and defined over time). If you want more detail, go to a search engine like Google of DuckDuckGo and enter : SMART goal.

For example, you can give yourself the goal of reading a book a month. I advise you to write a summary page for all the books you read. Scientific studies have shown that when you write the summary, you will remember more things and you will memorize more things than if you only read the book. Here are 2 scientific studies here  and there .

.

Check the book’s quality

books

To start, reading reviews on books that interest you on Amazon is a good place to start. It’s clear that it’s not done by experts but you can see people who like and hate the book. It’s up to you to do your own analysis of the numbers of positive and negative comments. If there are a lot of comments (at least a hundred), it’s a good sign.

It’s possible to access lists of books complied by people who read a lot of books. It’s obvious that these lists will never correspond at 100% to your objectives but it allows you to find pearls. If you want to train in business and personal development, Josh Kaufman’s Personal MBA  is excellent. It’s not necessary to like all the books of Personal MBA but most are extraordinary.

Action

Here is a simple exercise that I propose to you. Find 5-10 books of excellent quality that can help you achieve important goals for you. Determine a deadline (1 year) and calculate how many books you should read per month and how much time you have to spend every day reading.

I’m curious to know the books you found. Share this in the comments section and let’s go .

Subscribe to my newsletter and share this article if you think it can help someone you know. Thank you.

-Steph

Variant To Avoid Dumbbell Bench Press Shoulder Pain

shoulder pain

What’s up ? This is THE stephane ANDRE ! I watched an Athlean-x’s video  and I learned some good stuff.

I wrote an article about to avoid pain when you do dumbbell press or overhead shoulder press because I have a pain when I do it. Click here to read the article  . I have the same problem with the dumbbell bench press. I have pain when I do it, so I write this article to continue this exercise without pain.

Bench press is one of the fundamental exercises to build muscles but with this pain, I wondered if I should continue doing this exercise because it hurt.

Problem

The reason for this pain may be a biceps tendonitis, a torn labrum, an inflammation or shoulder impingement (inflammation in rotator cuff). All these problem create instability during this exercise while we know that stability (body’s stability and dumbbell’s stability) is very important to perform the movement properly.

In the case of a torn labrum, labrum is tied to the biceps tendon or rather the biceps tendon is attached to the labrum. During the movement, it’s the tension of the biceps tendon that pulls on the torn labrum.

Solution

The solution is to change the elbows position. To do the classic bench press, the elbows are at between 45° and 90°, dumbbell held horizontally in the hands and you press up. To calm the pain, we’ll change the position. The technique is to tilt the dumbbells so that the dumbbell’s back are facing the ceiling.

Classic dumbbell bench press

dumbbell bench press

dumbbell bench press

dumbbell bench press

Variant dumbbell bench press

variant dumbbell bench press

variant dumbbell bench press

variant dumbbell bench press

Tilting the dumbbell’s back does 2 things :

  • This brings your arms closer to your body because you use a semi pronated grip. With this position your hands and arms make your shoulders have a neutral position. It’s the equivalent of barbell corner press which helps to reduce the pain caused by dumbbell press .

  • You use your triceps more than your biceps during the movement. With the classic position, you use your biceps to stabilize dumbbells than your triceps. With this position, you flex your elbows so you use more triceps to stabilize dumbbells than your biceps.

 

 

dumbbell bench press
Classic dumbbell bench press

 

variant dumbbell bench press
Variant dumbbell bench press

Using more triceps than your biceps will seriously reduce the pain or make it disappear because there is less tension through the biceps and it will less pull on the torn labrum. If you have biceps tendonitis or inflammation, this will seriously decrease the pain. Try this technique and you’ll see that it will be the first time you’ve been doing pain-free bench press for a long time.

When I had this pain during this exercise, I thought of 2 options :

  • Stop doing bench press because you can’t support the pain anymore

  • Use lightweight

Now that I know this technique :

  • I can continue to do bench press

  • I can keep the same weights and increase them

Subscribe to my newsletter and share this article if you think it can help someone you know. Thank you.

-Steph

Boost Your Charisma

charisma barack obama

What’s up ? This is THE stephane ANDRE ! I watched an Olivier Roland’s video  and I learned some good stuff.

To increase my charisma, I discovered a completely counterintuitive trick. This trick is a state of mind. This is a trick that Seth Godin shares in his book « Tribes » . In this book Seth Godin explains the importance of internet. Internet isn’t just about doing business with customers/prospects, but it’s a real tool for building a tribe or community.

The principles for building a tribe or community with internet are to share quality content and to clearly explain your values to bring together people who share the same values as you. Seth Godin says something very interesting about charisma, he says that most people think that yow have to have charisma to get the idea when it’s the opposite. The simple fact of having the idea gives charisma. It’s deep right ?

In everyday life

 

everyday

 

I’m sure you’ve seen this situation :

  • There is a person who loses consciousness on the sidewalk Quickly a person must take responsibility for the idea of caring for the person who has lost consciousness

  • There is a car accident. Quickly a person must take responsibility for the idea of dealing with traffic to secure the area.

In situation where there is no designated leader, a person must take the initiative, without permission, to take responsibility for the idea of managing the situation.

As you can see, it does give charisma to this person and the others will naturally accept him/her as a leader and listen his/her orders, until the situation returns to normal.

The question, I’m asking you is : « In the project that is important to you, could you take responsibility for the idea of taking care of your tribe or community that shares the same values as you and to do evolve the project ? ». Tell me your answer in the comments section.

Subscribe to my newsletter and share this article if you think it can help someone you know.

-Steph

Machine Trunk Rotation

machine trunk rotation abs

What’s up ? This is THE stephane ANDRE ! I read a Frederic Delavier’s book « Strength Training Anatomy » and I learned good stuff.

Attention

Torso’s rotation in the machine are proscribed for people suffering from lower back or having already had a herniated disc, as they might aggravate or reappear this lumbar pathology.

machine trunk rotation abs

Standing on the turntable with your hands on the handles :

  • Rotate your pelvis from one side to the other, keeping your shoulders fixed and controlling the rotation. Your knees are slightly bent to avoid the risk of ligament stretching.

This exercise works mainly external and internal obliques and a little less rectus abdominis. Sets with high reps give better results.

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-Steph

No Longer Being A Victim Of The Modern Slavery

modern slavery

What’s this is THE stephane ANDRE. I watched an Olivier Roland’s video  and I learned good stuff.

Are you a victim of modern slavery ? If you have not yet asked the question, I will tell you the case of infopreneurs victims of modern slavery.

This is often what happens to people who create text, audio and video content on the internet. Imagine this case, a blogger decides to create his/her blog to build a community around a concept, idea or theme for weeks, months or years with free content. This blogger works hard to create free quality content and his/her audience grows little by little.

Fear of losing his/her community

 

fear of losing panic

After a few months or years of work, this blogger will propose something to his/her audience, it’s a paid product or a paid service. After all, all work has its merits. But for a minority of his/her community, it’s the scandal, people will make comments things like : « Actually, all you’ve done from the beginning was just to do business. You don’t care about your community, all you want is to make money, etc ».

At that moment, this minority who is scandalized by a paid product or a paid service, doesn’t realize that the message they say is : « Listen, we like you but all we want it’s that you work for us for free. We agree to continue reading your blog’s articles as long as your work for us for free until the end of your life ». The people who act like this are called supporter of slavery. But the craziest part of all this is that these people aren’t aware of this because they are not going to the end of their own reasoning. They react emotionally.

The problem is that we too often see infopreneurs let themselves be impressed by this. It’s normal to earn money to live with dignity, it’s legitimate to have this process because that is how a company works. The goal of infopreneurs is to create a company based on their passion. It’s important not to be negatively influenced by this small minority in the community.

So don’t let yourself be impressed by modern supporter of slavery. You must realize that people who complain are a tiny minority. The silent majority in your community find it normal and these people are motivated to buy your product or service. You know, the small minority who is never happy is always very noise.

You deserve that

 

you deserve it

And I have to explain something to you, it’s something you’ll only see when you sell a product or a service. There are people in your community who have been following you for months or years, and who buys what your offer simply to thank you for the good free content you have done so far.

When you have recognition like that, it’s priceless and you don’t worry more about the modern slavery’s supporters of the world. Live your passion by creating quality free and paid content because « all work has its merits » and if a person is not happy, you can share this article. It’s the same for an infopreneur who is afraid of losing a part of his/her community if he/she makes a paid product/service, share this article.

Subscribe to my newsletter and share this article if you think it can help someone you know. Thank you.

-Steph

Validate Data Mining In Tableau With A Chi-Square Test

validate validation

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

In this article we will start using statistics. Don’t worry we’ll do something simple, we’ll use the Chi-square test in a basic way. There is a special section to learn how to do statistics at an advanced level.

I’ll explain why we’re going to learn how to use the Chi-square test. The results we have with theses 2 bar charts are good. We see on theses 2 bar charts that age has a significant impact on the rate of client leaving the bank. We also see in which age groups the clients leaves the bank the most and which age groups the clients leave the bank the least. With that we have good insights.

In the A/B test « Gender », we can see that there is a correlation between the male and female sex and the choice to leave the bank. But as I said before, this A/B test is basic. The results of a basic A/B test visually shows us what is probably happenning in reality but we aren’t 100% sure of these results. To validate these results, we need do to use statistical tests like Chi-square test.

Doing a report based on basic A/B test is very risky and you can have completely false insights. I don’t advise you to do it (unless you want to leave your job). It’s for this reason that using Chi-square will help us to have strong insights.

Chi-square will allow us to know if our results are statistically significant. Our results are based on a sample of 10 000 clients and Chi-square test will tell us if these results are due to chance effects or if these results can represent all the client of the bank.

For example in our A/B test « Gender », we observed that in our sample of 10 000 clients, women are more likely to leave the bank compared to men.

tableau data mining science chi square test a/b test

Now, we aren’t sure if the results of this sample represent the behavior of all the bank’s clients.

To use basic Chi-square test, we use an online tool. Click here  .

tableau data mining science chi square test a/b test

On internet, there are plenty of websites to do a Chi-square test but we’ll use this one so that you can understand how it works. To do a Chi-square test, we need to use absolute values and in our A/B test we have percentage.

Let’s go back to Tableau. We’ll create a new tab with a version of A/B test with absolute values. In this way, we keep the A/B test with the percentages. Do a right-click on the « Gender » tab and select « Duplicate ».

tableau data mining science chi square test a/b test

Name the new tab « Gender Actual » to specify that it’s absolute values.

tableau data mining science chi square test a/b test

To have the absolute values, move « Number of Records » in « Measures » to the « Marks » area and put it over top of « SUM(Number of Records ».

tableau data mining science chi square test a/b test

tableau data mining science chi square test a/b test

Move « Number of Records » in « Measures » to « Rows » over « SUM(Number of Records ».

tableau data mining science chi square test a/b test

Cool, we have our absolute values.

tableau data mining science chi square test a/b test

We also need total absolute values, which means the total number of men and women. There is a very fast way to get that. Right-click on the vertical axis and select « Add Reference Line ».

tableau data mining science chi square test a/b test

Then in « Value », click on the drop-down on the right and select « Sum » to have the total sum of the observations.

tableau data mining science chi square test a/b test

And in « Scope », you select « Per Cell » option to specify that you want the total sums for each category, male and female.

tableau data mining science chi square test a/b test

Now, we have the total sum at the top of the bars. We will modify labels to have the absolute values. In « Label », we will change « Computation » to « Value » and click on the « OK » button.

tableau data mining science chi square test a/b test

tableau data mining science chi square test a/b test

Perfect, we have the total amount of observation at the top of each bar : 4543 women and 5457 men. We have what we need to use our online tool.

tableau data mining science chi square test a/b test

OK, I’ll explain how this tool works. « Sample1 » and « Sample2 » correspond to the independent variable « Gender ». You choose in which order you enter the data, « Sample1 » for men or the opposite. In our case, we use « Sample1 » for women and « Sample2 » for men.

« #success » corresponds to the result Y=1, which means in our case « yes, the client left the bank ».

« #trials » is the total number of observations, which means the total number of women in « Sample1 » and the total number of men « Sample2 ».

That’s how you enter the data :

  • For « Sample1 » in #success, you enter 1139 because there are 1139 women who left the bank. For « Sample1 » in #trials, you enter 4543 because there are 4543 women in total.

 

  • For « Sample2 » in #success, you enter 898 because there are 898 men who left the bank. For « Sample2 » in #trials, you enter 5457 because there are 5457 men in total.

tableau data mining science chi square test a/b test

Here is the verdict : « Sample1 is more successful ». « Sample1 » corresponds to women and #success is :« yes, the client left the bank ». This verdict means that of all the bank’s client, women are more likely to leave the bank than men. And look, there is something important, it’s « p<0.001 ». This means that the « p » is strictly less than 0.001.

tableau data mining science chi square test a/b test

« p » is the value that indicates whether an independent variable has a statistically significant effect on a dependent variable. In our case, the independent variable is « Gender » and the dependent variable is « Exited », which is : « yes, the client left the bank ». So « p » is strictly less than 0.001, which means that the independent variable « Gender » has a statistically significant effect on the dependent variable « Exited ». This shows us that out of the total number of bank’s clients, women are more likely to leave the bank than men.

This is how we use Chi-square test with this online tool. This is the same principle on all online tools that you can find on Google or DuckDuckGo . You can repeat these instructions that I gave you with other tools, you will get the same results.

It’s cool with the Chi-square we validated the A/B test and to specify that this A/B test is validated, we’ll color the tab in green.

Right-click on the tab, select « Color » and select « Green ».

tableau data mining science chi square test a/b test

tableau data mining science chi square test a/b test

Perfect, now we’ll validate another A/B test. Selects « HasCreditCard » tab.

tableau data mining science chi square test a/b test

We’re going to create an A/B test « HasCreditCard » only with absolute values. To save time, right-click on « Gender Actual » tab and select « Duplicate ».

tableau data mining science chi square test a/b test

We’ll remove the green color on the tab « Gender Actual (2) ». Right-click on the tab and select « Color » and « None ».

tableau data mining science chi square test a/b test

You rename the tab « HasCreditCard Actual ».

tableau data mining science chi square test a/b test

Move the variable « HasCrCard » over « Gender » in « Columns ».

tableau data mining science chi square test a/b test

tableau data mining science chi square test a/b test

Excellent, everything is ready to do a Chi-square test. We’ll remove « Exited » labels to better see the absolutes values. Make a click and drag out.

tableau data mining science chi square test a/b test

tableau data mining science chi square test a/b test

Perfect, let’s go back to our online tool. In this case, « Sample1 » is « no », which means client who don’t have credit card and « Sample2 » for « yes », which means clients who have a credit card.

That’s how you enter the data :

  • For « Sample1 » in #success, you enter 613 because there are 613 clients who left the bank. For « Sample1 » in #trials, you enter 2945 because there are 2945 clients who don’t have a credit card.
  • For « Sample2 » in #success, you enter 1424 because there are 1424 clients who left the bank. For « Sample2 » in #trials, you enter 7055 because there are 7055 clients who have a credit card.

tableau data mining science chi square test a/b test

Let’s look at the verdict, it’s « No significant difference ». « p » value is very high, it’s above 5%. This confirms that the independent variable « HasCrCard » has no statistically significant effect on the dependent variable « Exited ». That was the conclusion we had made when we had done the A/B test with percentages.

We had seen that there was 21% of « Exited » (clients who left the bank) in the category « no » and 20% in the category « yes ». With these results we concluded that most likely the variable « HasCrCard » had no impact on the rate of clients who left the bank. Chi-square test confirms our conclusion and we can put the tab « HasCrCard » in green to say that it’s OK.

Right-click on the tab « HasCreditCard » => « Color » => « Green ».

tableau data mining science chi square test a/b test

tableau data mining science chi square test a/b test

Excellent, now, you can do a statistical A/B test with 2 categories. Soon, we will do statistical A/B tests with more than 2 categories.

Share this article if you think it can help someone you know. Thank you.

-Steph