We’ve got a feedback story from our grateful customer who decided to share his success story and help students who struggle with the chi-squared test.

This article contains a full and really simple guide to solving chi-square. To keep his identity anonymous, we’ve changed his name.

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I’m Donald and this is my story about conquering chi-square. Einstein was completely right saying that, “If you can’t explain it to a six-year-old, you don’t understand it yourself.”

If you’re currently struggling with the chi-square test, I’ll answer all — and I mean all — your questions about this tricky statistical method in really easy to understand terms!

I’ve adapted this article from the “Methodology” section of my paper. You are welcome to use it to understand how the methodology of your own homework should work.

What is the Chi-Square Test and Where to Use It?

The first time I had to use chi-square was when I was at the 4th year of my undergraduate program at Pittsburgh University School of Nursing. I planned to prove that googling about mental health issues can cause anxiety and negative emotions.

Thus, the topic of my paper was “How reading of online resources about mental health issues impacts patients’ mental and emotional state”.

I surveyed 100 patients. I asked them how often they read about health issues, and whether such a guilty pleasure triggers their anxiety. Then, I recorded their answers on a table.  

All I needed was to find the right statistical test. I looked through a short chi-square guide online and it totally triggered my math anxiety.

You know, I felt that I’m the dumbest person in the world. Thankfully, I did not give up and continued.

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At the end of the day, Donald resolves his case — being mentored by a professional Nerd.

Let Nerdify find your perfect academic match using AI! ?

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❓ What is the Chi-Square Test?

First things first, I got to know my enemy. Chi-square test is a common statistical method used to determine whether two things (in statistics they are called variables) are somehow related.

❓ How to find out whether variables are related? If one variable somehow changes, and another immediately changes in response, it means that they are related.

This is actually very simple to understand once you put the concept of chi-square in the context of a real example.

In my case, patients would be reading about health issues online and experience anxiety. If they feel bad after browsing horrifying symptoms of mental illnesses on WedMD, that means these variables are related.

To make sure that the chi-square method suits your particular research, check these criteria:

1. You need to analyze numerical results — specifically, the numbers of times you’ve observed something happening, or how many people gave the same response.
2. Variables are categorical — variables should belong to specific groups. For instance, respondents in surveys can be categorized by gender, age, political views, etc.
3. There are two individual variables (e.g. how frequently people google online about mental illnesses (very frequently or rarely) and the effect of their googling (increased anxiety or no negative emotions)
4. You only need a “yes” or “no” answer – chi-square can only tell if two variables influence each other. It never tells how strong the influence is and when or why it occurs.

Chi-square is used pretty much anywhere because it is a simple, suitable for any sample size, and cheap way to test whether two variables are related. For instance:

 

• In healthcare: is anxiety associated with online research about health issues?
• In sociology: is crime rate related to the poverty level in a specific region?
• In marketing: do sales depend on the region where products are sold?
• In politics: does voter turnout depend on voter age?

Given all this info, I decided that chi-square was exactly what I needed for my research. But how to convert my data into a table and then get all the calculations done right? After 5 days of trial and error, all I had was only errors and I got stuck.

Why Chi-Square Test is Mistakenly Thought to be Difficult?

You’d think that the good old Google knows everything, but nope. Page after page of the search results, I saw the same explanations by-the-book, which were all Greek to me. Without statistical education, I got the theoretical part but was completely lost when it came to practice.

Then a friend of mine recommended me Nerdify. Nerdify connected me with a perfect Nerd — a Master in Medical Statistics and finally, I knew I was going somewhere!

A detailed explanation from the Nerd on how chi-square works and how I should use it — it was all that I needed to nail my super difficult paper.

Why was chi-square so difficult for me? As my Nerd said, it happens with all the students for the following reasons:

• Extremely complex definitions and explanations that make chi-square seem very entangled and confuse students
• Without illustrative examples, complex formulas are overwhelming for anyone who does not have a fancy for math.
• Lack of time teachers can devote to explaining every topic — students often have no one to ask for an extra explanation
• Lack of knowledge due to that your major doesn’t have anything to do with statistics. As a student nurse, I didn’t have any background in studying statistics at all.
  

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  Want a Personal Nerd to step in and make your test easier?

• Explain formulas?
• Provide real-life examples?
• Mentor customization of statistical methods to your project?

 ? Message Nerdify to get help!

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If you’re struggling just as I did, for whatever reason, I’ve got a perfect step-by-step guide to chi-square that you can use!

Really Simple Step-by-Step Chi-Square Guide

Right off the bat, you should know that it’s totally acceptable for non-statistics students to skip doing all the calculations manually and use online chi-square test calculators.

However, my college professor required all the chi-square formulas explained in the paper. Thus, if you’ll use chi-square, you need to understand this method to interpret the results correctly.

▶ Formula Explained

When you see this abomination of a formula, you probably think it’s extremely complex:

where

• χ2 — value of chi square
• Σ — sign of sum, means the total amount of elements in a sequence
• O — observed value of a variable, or the numbers you already have from observations or task description
• E — expected value of variables you need to calculate yourself; they represent how the variables would be distributed if there would be NO relationship between the variables

Even if you do all the calculations using MS Excel or SPSS, you still need to know where to put which number!

In sections below, you fill find out more about where to find these numbers.

Now it’s time for the best part — calculations!

 

0️⃣ My Case ➕ Sample Size

In my research, I surveyed 100 patients. I asked them how often they read about health issues, and whether such a guilty pleasure triggers their anxiety

• So there were two categories of patients: those who frequently research health issues and those who rarely research them
• There were also two options of their emotional response: increased anxiety and no changes  

Right now, I know my sample size — the number of observations. How many people responded to the survey? How many times you’ve seen something happening during the experiment or study?

In my case, sample equaled 100 — the number of people who participated in the survey.

 

1️⃣ Creating a Chi-Square Table

Using this data, I created this contingency table:

❓ Contingency tables present observations in matrix format — rows and columns, just like the table above. This type of tables is very commonly used in statistics, especially because it demonstrates how two variables are connected.

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	Increased anxiety	No changes	Total
Frequently research
Rarely research
Total

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2️⃣ Choosing Statistical Significance

If you’re writing a paper using the chi-square method, chances are that the level of statistical significance isn’t given. Where do you get it? You choose it yourself!

❓ Statistical significance — is the likelihood of that the relationship between two or more variables is accidental and the results of the observation are caused by something else than just chance.

For instance, if a patient gets anxiety every time he does online research about health issues, then statistically the probability of getting anxiety, aka level of confidence is 100%, or 1.

If a patient gets anxiety in 9 times out of 10, then we can confidently state that the probability here is 90%, or 0.9.

The most typical levels of significance are 0.05 and 0.01 — both are 100% safe to use in your paper. I chose 0.01 because the lower the value, the more significant results you’ll get — lower significance implies a lower risk of error.

Why do we need the level of significance? My Nerd had a good metaphor to explain it. Imagine that you have to climb up a ladder that has 100 steps. The more steps are missing, the higher the risk that you’ll fall. That’s why we set a very low level of significance — to make sure that calculations are correct!

 

3️⃣ State your Hypotheses

The hypothesis is a fancy word that confuses many students, but in reality, the hypothesis is just an assumption that you have. In chi-square, you’ll need 2 of them.

• Null hypothesis (H0)– usually states that the results of the observations could result purely from chance and the variables are independent — if one of them changes, another one stays the same and doesn’t react to the changes in the first one.

My H0 would say that getting anxiety isn’t connected with researching health issues online.

• Alternative hypothesis (H1)  states that the sample observations result not from a random cause, but from a specific cause and the variables are dependent in some way.

That is, my H1 says that patients really do get anxiety and experience negative feelings after researching health issues online.

4️⃣ Fill in Observed Values

Here just enter all the observed values into the table:

❓ Observed value — what actually happened or how many times you’ve seen something occur. For instance, how many respondents out of 100 admitted to frequently research online about mental issues and get anxiety from it

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	Increased anxiety	No change	Total
Frequently research	36	9	45
Rarely research	24	31	55
Total	60	40	100

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5️⃣ Calculate Expected Value

Here we calculate values that would be observed in case if there would be no relationship between researching health issues and experiencing negative emotions.

❓ Expected value — it’s calculated by the formula below and show what would happen if the variables were absolutely independent — wouldn’t affect each other at all.

where

• E — expected value
• Mr — row total for the cell you’re calculating an expected value for
• Mc — column total for that cell
• n — sample size
  

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	Increased anxiety	No change	Total
Frequently research	27	18	45
Rarely research	33	22	55
Total	60	40	100

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• Expected value for “frequently research, increased anxiety” E=45*60/100=27
• Expected value for “only rarely research, increased anxiety” E=55*60/100=33
• Expected value for “frequently research, no negative emotions” E=45*40/100=18
• Expected value for“only rarely research, no negative emotions” E=55*40/100=22

 

6️⃣ Calculate Chi-Square Using the Formula

Once again, you can use online calculators, but this how it’s done in practice (aka the hard way):

 

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Not ready yet to move further with chi-square test?

Find your Nerd to ease your pain. In anything. Unless it’s legal. ?

 ? Get Connected to a Personal Nerd!

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7️⃣ Calculate Degrees of Freedom and Critical Value

Now that we got chi-square calculation done, let’s calculate the degrees of freedom

❓ Degrees of freedom (df) — the number of independent variables that went into the calculation.

Just think of those promotions “buy 2 — get 1 for free!” — you’re free to choose several things, but +1 product is always set by the promotion. Degrees of freedom, however, subtract 1 from both your rows and columns.

You need to use a chi-square distribution table and find your critical value at the intersection of the degrees of freedom (df=1) and the level of significance (α=0.01):

So, our critical value is 6.63. This value is smaller than our χ2 =13.63 Therefore, in our chi-square test example, researching about health issues online and getting anxiety or negative emotions are related.

We don’t know how much they are related, because chi-square doesn’t answer this question. But we definitely know that they are somehow related.?

Chi-Square Calculators — the Easy Way

Even if you need to do all the difficult calculations by yourself, these calculators are awesome to verify your results. Or, if you’re lucky, online calculators are all you’ll need to use to calculate chi-square!

1. Social Science Statistics Calculator — easy to use chi-square calculator that can calculate up to 5 rows and 5 columns. You can enter category names, fill in the data, and get the result in a flash.
2. Kent University SPSS Guide for Chi-Square — if you have SPSS, you can consider your chi-square test pretty much already done. This guide will help you learn how to import chi-square tables and graphs into the SPSS and get the task solved. Many colleges and universities use SPSS as their default tool, and your professor may ask you to show your SPSS datasheet.
3. Chi-Square Calculator — another extremely simple online chi-squared test calculator. All you need to do is enter the observed values and you’ll get degrees of freedom and chi-square ready.

How Can You Nail Chi-Square: My Pro Tips

If anyone told me I would be able to do it just a week before connecting with a Nerd, I’d never believed it. It was simple and logical explanations from my Nerd that helped me completely nail chi-square test and do all the calculations by myself.

Now, I understand each step of chi-square and interpret results correctly. For me, it was crucial that a professional, with a background in studying and applying statistics in practice, would explain everything to me in human language, not math language.

And now a few tips for you to cut corners if you’re dealing with chi-square:

• Keep in mind that chi-square isn’t rocket science — it is doable and actually very easy if you have a really simple and detailed guideline
• The number of rows and columns can vary and your table can be much larger than mine, however, the principle remains the same — you’ll just need to do more arithmetic
• When calculating the expected value, you’ll most likely get fractions, which can confuse you, especially if you’re calculating the number of people in each category. Don’t bother about it — these calculations are intended for further calculation of chi-square

That’s all I wanted to share in my feedback story today. Hopefully, it will help you nail chi-square and get the grade you deserve! Chi-square isn’t as difficult as it may seem at first, so go ahead and break a lance!

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Of course, you can make your own success story too!

Nerdify is an AI-powered platform to quickly connect with the experience of 1000s of Personal Nerds

✨Give a try right now!

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This time Nerdify decided to speak up on a kinda tuff theme: a decision to drop a class.

When a college student feels like dropping a class, the moment comes with an endless stream of questions, apprehension, uncertainty, and stress. It does not matter whether you have registered for a class that was not exactly what you have expected or you cannot cope with a part-time job and doing well in each class, – you still want to know when (and if!) a decision to drop the class has to be made. The choice is never an easy one because it may feel like you have given up your future and failed. No, it is not the case and it does not mean that you are not smart enough! On the contrary, it is an important decision that a student can make due to a variety of reasons. The question is in how will it affect the graduation schedule, financial aid, and your life in general.

Dropping a Class or Withdrawing?  

Before we dive into the depth of decisions and the reasons, let us learn the difference between dropping the class and withdrawing, which is not always the same! The difference is that the majority of colleges and universities have a clear policy, which allows for two week period to add or drop the class at the start of each semester. It is a period that allows you to schedule your classes and carry out the changes without a penalty. If you choose to drop the class during this particular period, the class will not appear on your official transcript list. In other words, there will be no sign of your enrollment anywhere. However, there is one thing to keep in mind that relates to financial aid program! If the class is dropped, there is a return of funds policy that may come in power in most cases. Now when the two weeks period is over, your action is defined as withdrawal, which is an entirely different matter! To cut the long story short – your official transcript list will have a “W” mark next to the class you have withdrawn from.  

Some Things to Be Aware Of:

If you choose to withdraw from the class or drop it, as most students still refer to the practice, you should be aware of the following:

• It is possible that you will be charged for tuition fees in certain conditions, so make sure to review the terms and conditions before you make a final decision.
• Keep an eye for specific dates and the deadlines that you have to follow! Make sure that your schedule with the other classes is not affected by the change.
• Your overall progress may be affected in case you do not have a sufficient amount of study hours.
• While you will have a “W” on your graduation transcript if you withdraw from the class, a “W” grade in any class dropped will NOT affect your GPA!
• In order to receive a financial aid from your college or university, you have to complete at least 70% of your classes taken successfully. It means that F or W is defined as unsuccessful, unlike D or anything better!
• You need at least twelve credit hours to be considered a full-time student. Do not ever drop below 12 credit hours, so you do not find yourself in a situation without insurance and financial aid!
• Check with your college or university about special class dropping policy in terms of your progress through the semester and other rules that may be applicable!

Before You Drop The Class:

Before you decide to drop the class and implement changes to your life and professional career, always talk to your college advisor first! One of the crucial reasons to do so is that they may be aware of specific implications and future challenges that you may not even know about! As you talk to the advisor, make sure that you ask these questions to help both of you to decide what to do and see whether it is right or wrong:

• Will dropping of this particular class affect my graduation date and an overall academic schedule?
• Are we dealing with a prerequisite course that a student can only take once a year?
• Is this particular class necessary for graduation this year? In other words, if you already two semesters close to graduation date, your decision may affect the day.
• Will dropping of this class affect my financial aid support and the scholarship?
• Will I have fewer credits in total? If so, how will it affect my financial state and is there a funds return policy?
• Will dropping a class influence my full-time student status? It is always better to ask because it affects your applicability for financial student aid and a scholarship among other things your college or a university may offer!

Now it is only you who can decide whether you should drop a class or not, therefore, ask yourself these three simple questions:

• Why do I want to drop the class and what is the true reason for that?
• Can I settle down the issue without dropping?
• What kind of help and what changes do I need to continue with the class?

While it is hardly possible to list all the reasons that may be suitable or not suitable for dropping the class, it is most likely because the class seems to be “too difficult” or you “have to work and just cannot manage it all”. No matter what your particular case is, let us deal with the aforementioned situations and see what can be done.

You are trapped in a situation when you have to work way too much to keep yourself going or to earn a little extra. The first case is a reason to ask for additional financial aid if you are determined to do your best academically, but financial struggles get in the way. Now the second case is not really worth ruining your studies because it is much wiser to avoid dropping the class and focus on your long-term goals instead of treating yourself with additional earnings. Ask yourself about what matters more to you, but remember that it is your life and that studying well always rewards you in the future!

Now the second case is when the class seems to be too difficult or not what you have expected it to be. If it is the first case and things seem unclear to you, remember that dropping a class is not the best solution since you can ask your university tutor or a college professor for help. A bit of a guidance and a list of your concerns addressed may help you to receive that missing link to feel better about the class and see all the benefits. Challenge yourself and try to learn more about the class while you can! Still, if the class is really not what you thought it would be, talk to your academic advisor to weigh in all the pros and cons, read of the possible consequences, and do what you feel is best!

Several Valid Reasons to Drop The Class:

• You need to drop the class in order to maintain your scholarship.
• You do not have sufficient time to complete the class due to personal circumstances.
• Dropping the class will not damage your overall academic progress.
• You have a sufficient amount of credit hours and you can safely switch the class and make changes, while there is a “two weeks” period.
• You are dealing with a military duty.
• Adding a different class will be more beneficial to you!

Do not forget that when you struggle with a particular class, there are still special rescue courses that usually start in the middle of a semester! However, if you have to deal with an illness or major changes in your life, the best thing you can do is withdraw from all classes entirely. Likewise, with the military duty, you can apply for special programs that meet your situation and allow you to receive all the necessary credits.

Even if you decide to drop the class and have already talked to your college or university advisor, always sign up for the rescue class and give it one more chance! Trust Nerdify, talking things out always helps to see the situation clearer and do what’s best for you!

It has been a packed weekend, hasn’t it? Thanksgiving, Black Friday, Cyber Monday (Nerdify’s marketing has been busy) – lots of holidays smashed together in such a short period of time. We do hope these few days have been a blast for you, guys 🙂

Now, it’s time to get Nerdy again 🙂 We thought it would be a good idea to tell you some secrets behind the success of the biggest names in the tech industry today. How did people like Jeff Bezos (who’s fortune recently surpassed $100 billion) and Steve Jobs manage to build such large companies?

We have done a thorough investigation and here are our findings. These are general rules that can be applied pretty much everywhere, no matter what you want to do in life.

Perseverance and passion

These 2 points have been cited by everyone – Bezos, Jobs, Obama, Buffet and many others; and we think these are literally the most important factors for success – having a passion for what you do and having determination and tenacity to work hard for a sustained period of time. These two go hand in hand because it’s passion that gives birth to perseverance.

As Steve Jobs once said – “it’s so hard (to create anything) that if you don’t have passion, any rational person would give up. You have to work really hard for a sustained period of time. And if you don’t love it, eventually you are going to give up.” And that’s what happens to most people. Lot’s of people start projects/businesses, but eventually, a good chunk of them give up, when problems start piling up on their desks.

Jeff Bezos, when setting up his private spaceflight company Blue Origin gave it the following motto – “Gradtim Ferociter” which means “Step by step ferociously”. This is how he explains statement: “You can’t skip steps, you have to put one foot in front of the other, things take time, there are no shortcuts”. People who persevere, eventually get sh*t done, which ultimately leads to success.

Don’t be afraid to fail

This is a very popular reason why people don’t want to start new projects/ventures – they are afraid that they will fail; they are afraid that people will judge them as a failure if they don’t succeed on their first try.

The reality is different, however – people who never fail, are the ones who never try anything. In fact, most successful entrepreneurs in the world have failed a lot before they’ve achieved great success.

Take Mark Zuckerberg for example. He said: “I have made so many mistakes any mistake you can think of, I’ve made it. But if you’re building a product that people love, you can make a lot of mistakes”. Today Facebook is worth more than $500 bn. Not bad for a “made all the mistakes you can think of” scenario, right?

Jeff Bezos said, “I’ve made billions of dollars of failures at Amazon”. His reasoning is that continuous experiments (bold bets as he calls them) will not only offset any losses you make from failures but will eventually lead to high profits (because you would have acquired so much learning and knowledge from your failures). Companies that don’t promote experiments and are not prepared to fail from time to time, will eventually die. The important part is to learn from your mistakes.

Everything around you was built by the same people as you are

Steve Jobs once said: “Everything around you that you call life was made up by people that were no smarter than you. And you can change it, you can influence it… Once you learn that, you’ll never be the same again”, meaning that you don’t have to be special to act – you just need to have the will to get the job done 🙂

Nerdify’s Conclusion:

• The core of success is perseverance -> being able to work hard and staying focused on achieving your goal.
• In order to do that for a sustained period of time – you have to love what you do, or at least have an inner fire in you that disagrees with the status quo that keeps pushing you forward.
• Don’t be afraid to fail, it’s all part of the learning process.
• Finally – everything around is built by the same people as you are. You are just as good and as capable.

Good luck, guys! 😉