How To Know Which Statistical Test To Use For Hypothesis Testing

[@quantquill]

We do not use a t-test for a one-sample test for proportion. We use the z distribution. I teach undergraduate and graduate statistics and have reviewed a dozen statistics textbooks and with 99% confidence, claim that we do not use the Student's t-distribution when testing a proportion. From the Stats Stackexchange: "The reason you can use a z-test with proportion data is because the standard deviation of a proportion is a function of the proportion itself. Thus, once you have estimated the proportion in your sample, you don't have an extra source of uncertainty that you have to take into account." Z distribution doesn't ask for sample size to determine the critical value, whereas t distribution does. However, as sample size gets large, z and t converge until t = z. For example, the sample size of 1000 would have no difference between z and t values.

[@AmourLearning]

Thank you for the correction 🙂

[@fatriantobong]

The z-test for proportions is DERIVED from the binomial distribution under the assumption of a large sample size. The key idea behind this test is based on the Central Limit Theorem, which states that the distribution of the sample mean of a large enough sample will be approximately normally distributed, regardless of the shape of the underlying population distribution. hence you use z-test with proportion data

[@beachwave5705]

ok tryhard

[@mrbenizzle4087]

@@beachwave5705that’s such a bananas thing to say to a professor making a correction to a statistics video on KZbin 💀

[@CraigThePoet]

I took the data analytics course on Coursera and they also taught to use only a z-test for proportions. Rushed to the comments for confirmation so thank you lol

[@aflowerthatbloomsinadversity]

Spent 16 weeks in a graduate level stats class, but learned everything I needed to know in this 20 minute video. Thanks! Super clear.

[@AssGasGottaBlast]

Came here to say the same thing! lol

[@konami584]

yes, agree :)

[@biruktesfaye7472]

Those 16 weeks has laid a huge foundation for u to understand this 20' lecture easily though.

[@Noname11364]

Right? I was thinking in class, there has to be a more concise way to explain this stuff.

[@cjohnson3836]

Given its a year later, you've probably now also learned that none of these tests are relevant any longer.

[@Misterz3r0]

There is nothing wrong with the 1-sample z test. It produces the correct answers as long as you have the population parameters. But because we rarely have the population parameters we don't use it. Its not inherently flawed as implied by the host of the video. It's pretty easy to explain why it isn't used very often, like I just did. Otherwise, great video.

[@Canuck1000]

I was going to say the same thing. In addition, when the sample is greater than 30, both tests are pretty much the same. For the Chi-square, he should have said that each "bin" needs to have more than five observations. Two of them were below five.

[@sssam844]

@@Canuck1000 he seems to be quite incompetent

[@claireli5044]

@@Canuck1000do you know the difference of 2 sample t-test proportion vs chi squared? I feel they are quite interchangeable, like the depression example he mentioned. Can it be used for chi-squared as well?

[@Canuck1000]

@@claireli5044 The issue that is discussed here is the z-test vs t-test (population vs sample). The z-test is valid if we know the information about the entire population, but is very difficult to obtain as Z3r0 said above. It should not be automatically rejected. In the end, if n>30, both tests will give you the same results (if it is a sample still use the t-test though).

[@hyowonkim8168]

@@claireli5044 Hi, isn't the t-test for comparing the means of two or more different continuous variables and the chi-squared test for nominal and/or ordinal variables? If I am not mistaken I don't think they are interchangeable. I would appreciate it if someone can correct my understanding. Thank you.

[@aishwaryar1998]

The fact he explained the entire semester statistics portion in 20 minutes clear and precise. Amazing 🔥

[@HamzaAfridi999]

As a medical student with a small portion of statistics I m just confused 🥲

[@BillyMathews11590]

Dude I spent $70,000 on a PhD in Boston and could have saved every penny had I seen this before. Thanks your fantastic.

[@siddharthvm8262]

Great video! Just wanted to share my 2 cents. We don't use z tests because they require for us to have the population statistics (population mean and standard deviation) to do our analysis whereas in a T-test we just require the sample statistics (sample mean and standard deviation) to go ahead. Since in many cases we are just comparing 2 samples and we might not have the population statistics (especially standard deviation),we use T-tests instead of the z tests. Hope this helps!

[@raideryvs5595]

Just to add a little more, you dont need the population mean to perform a z-test but you need the population standard deviation (which you never really have in practice). If you needed the population mean, then doing a test for the mean would be beyond pointless

[@anuragnegi9636]

@@raideryvs5595 not sure about this. What about a case where a machine is claimed to produce products of size X and we have to look at a sample's Mean and Std to validate that ? Here we have 'claimed' population mean available to us.

[@LengForChrist]

I am from the university of Jos, Plateau State, Nigeria and l have never learned well during the masters degree statistics classes l took for one year+ but you make it look simple. You are a good communicator and l feel more confident about my statistics knowledge because of you.

[@HenetuNoel]

🇳🇬❤

[@jennifervazquez5329]

saved me so much time researching the appropriate technique I should use to test my hypothesis. Glad i watched it

[@fatemehlh]

I’m on a PhD level program with a statistics course and this is incredibly useful sir. You deserve 22 million subscribers!

[@haidaralolaywi8557]

Same as here

[@antoniorobinson1727]

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[@prithvidhyani2002]

no offense but how is any of the information in this video useful to you while doing a phd in statistics? isn't this taught in high school statistics?

[@joed2444]

@@prithvidhyani2002 Maybe in your high school. Some of us are still learning the basics at the graduate level.

[@prithvidhyani2002]

@@joed2444 ohh I see. I should add then that this video really only tells you things to memorize about these topics. If you dive deeper into the mathematics behind every statistical test, you will not need to remember what test to apply in which situation, it will just make sense. Just my two cents if in case you are interested in studying stats.

[@srishtichauhan111]

Thank you so much for simplifying the most confusing portion of whole statistics class. You are doing a great job !!!

[@TheColorField]

You use the Z-test when you know something about the population standard deviation. This doesn't happen very often, so the t-test is more common. Saying you should never use it, or that it's "bad" or "dumb" or "unprofessional" is just NOT accurate. It's just more RARELY used. Throwing it out shows a lack of understanding.

[@jamiyana4969]

Simply the greatest explanation. I spent hours trying to get the main gist and difference of all these confusing test. This video was the brilliant saver for me. Thank you so much !!!!!

[@uncutit1995]

Woow woow this is the most clear version of understanding which test, when, where and how to use the statistical test. Thank you

[@ladydove5895]

Where have you been all my statistics life? WOW!! Just brilliant...thank you so much.

[@jermelpurse3018]

I’m not statistician but I’ve been in the statistics classes at least all three or four you might take during your undergraduate year and when you learn about those particular test they also tell you when you should use them. That’s part of learning about the actual test. I think that’s where we’re having a breakdown in the education process now statistics is more college level but even on a more basic level we might learn how to do math but we don’t learn the principles behind the mathematics you should learn the principles behind the statistics tests then you know when to use them

[@julianmcneil9769]

I'm another doc student who just learned some new things! Thanks!

[@andrestorres7343]

that's so valuable... "Don't use z test cause I don't like it, as it makes some assumptions I don't want to talk about..."

[@erhancinar5954]

Wow. Great introduction. The context is great. But apart from the context, the teaching style is fabulous. Thank you.

[@ifeanyi_maduka]

This is by far the best approach I've watched on youtube. And I've watched many. So, straight sub and like for sure.

[@girlwithquestions]

This was super helpful in so many levels. Not only did you described the tests in detail without hassle but it helped me understand when to use them. Thanks!!

[@antoniorobinson1727]

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[@hennanoor6346]

omg have an exam on Tuesday and this was a lifesaver!! thank you!!

[@eagelnest721]

For whatever distribution shape of population, you take a sample of size >25, the average value (mean) itself is normal distribution, and you use Z-test. For a smaller sample size, we need to consider degree of freedom, then you use t-test.

[@rhoninpowers]

Here it is.... (love youtube) I figured if I looked long enough...someone will have stumbled on some of the reasons why Z-Tests are still used quite often. Outside of this however...very clear explanations some of which I enjoyed revisiting from my days long past doing this stuff regularly.

[@LauraGayusi]

Thank you very very much I have an exam tomorrow and you explained it clearly that I understand now I really appreciate your efforts you are a genius thank youuuuuuuuuuuuuuuuuuuuuu

[@daiversetech8000]

The energy you bring to lectures is contagious. The explanation is extremely clear. Great stuff. Please keep it coming. Thanks

[@bryanlee5464]

wish all teachers are like you can structure so clearly and simply like this!

[@antoniorobinson1727]

Hepatitis virus can be cured naturally... visit #herbalistehi for review and to be cured too no matter the virus or disease

[@fatmazehra3892]

It is amazing! While I listening, I made a mind map and I finally organize my knowledge. Thanks a lot!

[@KatoOnTheTrack1]

I’m a mechanical engineer. Of course we took the appropriate statistics and probability class but never saw the real significance until my 5th year of being an engineer and working at GE healthcare. Now I apply the DMAIC approach as much as needed.

[@BNT05]

You are damn right, buddy! I had such a similar experience, and I believe to many out there! I found that the DMAIC thing of LSS is so interesting. So, you are practising it within the healthcare industry? Wow, that is great!. Maybe we can catch up for more experience sharing...😊

[@laureldennis1727]

Ok, first, I love the way you present the information = terrific!!! 2nd soooo easy to understand; you speak in everyday language. thank you so much for this video, I got it!!

[@xanmos]

You mentioned in 4:40 about t-test for one proportion, which DOES NOT exist because Z-tests for proportions are based on approximation of normal (hence, z) to binomial distribution so it's only z-test for proportion. In times like the sample size is so low in testing a single proportion, then some nonparametric test may be used, like the binomial test.

[@hoaralatoan845]

Thank you so much. My statistics semester packaged in your 20-minute video.

[@JamesPavlaine]

there is no equivalent t-test for one sample proportion due to the binomial approximation in these cases so only z -test for one proportion samples

[@solarchannel7943]

Good Thank you.

[@Kashantthev405]

Hi Sir, i need your help. From below info, what you understand. Can you explain to me, pls? Hypothesis i) There is a positive relationship between salary and employee retention - BETA VALUE (-0.379), Pearson Correlation (-0.289) Result : Accepted ii) There is a positive relationship between communication and employee retention - BETA Value (-0.159), Pearson Correlation (0.110), Result (Accepted) iii) There is a positive relationship between job satisfaction and employee retention which impact their decision to stay : BETA Value (-0.115), Pearson Correlation (-0.136), Result (Rejected)

[@BNT05]

Thanks so much for sharing the knowledge... for FREE! However, one of my statistics teachers, used to say to me to use t-test for a small sample size i.e., of less than 30 with unknown standard deviation of a population with a normal distribution property. That explanation still holds?

[@mcyap92]

Clear explanation, good example, energetic lectures! Thanks, this is so helpful!

[@hiyaguha]

Kody, Thank you so much. I have spent days trying to figure out ANOVA versus Chi Square versus T tests and so on, and you made it so easy. I am really grateful --and also a little baffled that so many other sources make it so complex.

[@jumaayubumohamedi4813]

I think proportions are for categorical response or variables and not qualitative as said here, qualitative research itself its so much complicated with thematic or content analysis of codes and quotes, regarding Z and t test I think its about sample size that dictates which one to be used, I stand to be corrected if I am wrong

[@hit4success]

Hello, This lecture has helped me to understand using T and ANOVA Test on categorical variable. Previous my thought was T and ANOVA is used only for MEAN difference.

[@antoniorobinson1727]

Hepatitis virus can be cured naturally... visit #herbalistehi for review and to be cured too no matter the virus or disease

[@BipolarShango]

If this video existed when I was in Uni I would definitely have made a better grade. 😭 May the good love save us from crappy lecturers

[@louiechievonmendoza9398]

I commend you! This is the most comprehensive comparison with explanation so far. Thanks

[@zeynepzisan3636]

What a clear explanation with examples. I could understand without statistic background. Thank you

[@MsAndreaskastrup]

Amazing! So much easier and fun to follow along than the other youtube videoes i have seen

[@sirmarky9991]

Your reaction on the thumbnail is definitely me.

[@dr024]

Theres no such thing as t-test for proportion. As tests involving single and two proportions, which are technically binomial, may only be estimated by a normal distribution (hence, z test), and not by t-distribution.

[@DigitizedSelf]

I'm amazed that there are not more comments on this.

[@dr024]

@@DigitizedSelf @DigitizedSelf im amazed too that there are 200k+ who viewed this and 5k (who "liked") who are totally no knowledge.

[@rustytulod1449]

t test also follow the same formula with z test.

[@dr024]

@@rustytulod1449 find a book that use t-test for proportion and ull never find one.

[@chandanaanil2249]

LOVED THIS!!! NEVER UNDERSTOOD STATS BETTER

[@akanshasrivastava3001]

Honestly ! I wasn't sure about it. But the content is so simplified,relevant and helpful.

[@captain486]

thanks man, this video helped me a lot doing my graduation research.

[@MaryamSadatAleali]

Thank you so much! I wish every statistics class started this way. Getting to look at the bigger picture first and then jumping into details is always a better way to learn things.

[@koenhouse]

You are one in a million! I finally understand when to use Regression! Thank you & subscribed!

[@drj144]

Bro i cannot thank you enough. You explained it very clearly for me. Tq boss

[@jobreycatungal530]

Can we use Z distribution for correlation and Regression?

[@sorormimm493]

Ugh, hated stats in grad school. Both rounds. Am fascinated by stats now!!

[@theTchild]

Before i even finish this video , THANK YOU!!

[@germb747]

Thank you! You explain this so much better than my professor does.

[@hls_yeah]

When he talked about the 2-independent sample test for mean, 2-independent sample test for proportion, and paired sample test, are those all t-tests just with different null and alternative hypotheses? Or are there different ways to do those tests other than the t statistic?

[@phipkin5674]

everyone in the comments are saying that some tests are 'better' to use than others ( t test is better than z test) but i have always thought that each hypothesis test only had 1 test/method that you could use. do some exam questions have multiple tests that can be done on them to get the same result and if so what tests can be used instead of others. thanks

[@phoophookaren]

Hi Amour, what do you use to write in this video? what type of tablet(+pen) are you using here?

[@VV-xf6fg]

Brilliant! You saved our time. Thank you!

[@amoe66]

Z test for proportions T test for means Chi Squared Goodness of Fit for 1 sample with 1 variable to test if it is different for the population (ie test if the distribution of race is different in 1975 population to the 1980 sample) Chi Squared Independence for 1 sample with 2 variables to test if they are independent (ie test if chess and IQ scores are associated) Chi Squared Homogeneity for 2 samples with 1 variables to see if they have the same distribution (ie to test if men and women have the same distribution of living arrangements) T test for slope

[@Victoria-tc5cm]

Hopefully, I can gain a better understanding of this topic. My 2nd take with Probability and Statistics for my undergraduate degree in Psychology (Science) via Online.

[@michaelloui1860]

Hi there! How to know which tests are used in undergraduate and graduate classes. Thanks!

[@apollicino2824]

Are there stats practices that take outliers and/or miscategorized people in a study into consideration? For example, often times the example of men and women is used, but that leaves out trans and intersex folks...In a test that is only looking for men and women, nonconforming people would either get absorbed into either data set (possibly skewing the male and female categories) or show up as an outlier that often times gets excluded. If you are interested in specifically studying minority or marginalized groups, or just want to make sure your data of dominant groups is not skewed, how do you account for miscategorized people in a study or outliers that may carry important data?

[@allaboutbiology712]

Kindly give some explanation about ONE-WAY ANOVA test ...why we use this test ? Amour Learning

[@ralmond25]

I typically use the t-test for means (and similar statistics, e.g., regression coefficients), but the z-test for proportions. That is because I'm assuming the error model is Binomial, and the normal approximation to the binomial does not require me to estimate the standard deviation, and hence the right distribution under the null hypothesis is approximately normal (by the Central Limit theorem). Note that I often use a chi-squared for proportions, especially when comparing them across different groups.

[@mariasahina9657]

Thank you! I'm in graduate school now and your videos still help!

[@antoniorobinson1727]

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[@LiliaceaeLilium]

That really helped me understand the differences. I've always struggled with that before, so thank you!

[@synergi1107]

thank you so much for finding time to really explain this to us

[@tbrazz8482]

This was extremely helpful and clear...thanks so much!

[@cosanostra8341]

Thank you for the explanation!! A quick question please: I measured the hardness of a material 2 times (before and after heat treatment), then I represented it with 2 box plots. Now I want to compare the 2 box with each other. For this I need to know when the boxes are significant. Can I use Chi square method? by the others technics, icant calculate p.value with exel. Thank you again!!

[@maxpatrickoliviermorin2489]

Besides a couple of mistakes, good explanations! Thanks! You lack theoretical grasp apparently, but you've got great practical understanding of the concepts. I'm not sure the z-test is as biased as you think and, therefore, completely useless. You need to know the parameters of the actual population in order to use it. That's probably why it's less common.

[@cremildamondlane3900]

hi, i did math stats, anova and regression end of last year, this year i did stochastic and im currently doing time series. I want to deepen my statistics knowlege any sugestions on which courses i should do next?

[@sanskarkhandelwal]

I learned more in this video than 4 month's of college classes 😂

[@JeevanDeepB]

Pure gold content😍

[@arj123sub]

Thanks for posting this video. Clarified the difference between the tests

[@MrRemava]

Great! Simple and short resume of a difficult problem. Thanks a lot!

[@luisrodrigueziii7316]

My friend, you are AMAZING. Thank you so much for this video.

[@antoniorobinson1727]

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[@anatorri6812]

You are a genius!! Thanks for your video!!

[@kamogelokhumalo4792]

WOW thank you very much for that easy to understand explanation

[@kevinshao9148]

Great video of lecture of this young man! Thank you so much!

[@rhasanvand1359]

Ery good explanation You made it very simple thanks

[@VikramKumar-yc5rl]

I have 3 independent groups (standard drug, new drug, combination of both) to test a eye drop drug trial. I need to test the significance of new drug for various symptoms( itching, tearing, burning sensation, etc; total 10 symptoms ). I have before and after data for each symptom. Sample size for each group is 13,14 and 15. Which test should I use? To choose test do you I also need to know the normality of data distribution?

[@chumbleychannel96]

He's secretly the god of statistics

[@tnmyk_]

Very well explained! THis video is super useful! THank you very much!!!

[@FallenJakarta]

you are the real MVP

[@savagesammie8923]

Watching this before my stats final, wish me luck

[@planetarygodzilla]

Straightforward.

[@aaronquinn8241]

Z tests are used to determine critical values in samples greater than 30, that has nothing to do with what hypotheses are being tested. As you even demonstrated about the Apple users, if you had the slightest notion that their user's mean age was less than states, you could draft appropriate hypotheses around this no?

[@little___artistic]

Thanks for this lecture! You are doing great!

[@suki1053]

Thank you so much!!!!! This is definitely solved my problems and answered my confused.

[@antoniorobinson1727]

visit #herbalistehi for review and to be cured too no matter the virus or disease

[@Diana-Trans2Scribe]

Kody please help! I'm doing a project in SPSS I'm so confused. I have a group of participants pre and post-intervention but my variables are not continous, they're not scale, they're categorical. Does it matter if I use the paired sample t-test? I also have a 24question survey, so do I pair all questions are pre and post? Do I actually have to enter 24 pairs? Sorry if this is a stupid question but I took stats a few years back and I'm so confused. This is a phd level dissertation and absolutely no help is given to me. I'm losing my mind.

[@horsenaturalbaby]

Look up spss on KZbin you will find a good answer there

[@renitaforney6754]

I have a question for you. If I am looking to determine the effectiveness of a medication taken along with another medication or taken alone against a placebo which test will I use? Help!!!

[@abhisheksrivastava3270]

Great video Please clarify what type of test one can use if studies are going on journalism and media comparisons

[@edwinimfumu3221]

Question. I have data of monthly (total) child death for 2020. Which statical test to run in order to see whether the change is statically significant.

[@meggie0098]

Say I did 2 quantitative questionnaires. One for police perception and one for public perception. My data is non-parametric. What test would I use to compare their responses?

[@a.alheraky4018]

why is the 2-sample independent test different from the 1-sample t-test? In both cases you're just comparing two distributions with each other? Why does it matter that they are two different samples vs. two different subsamples from one bigger sample?

[@PLuna-zb4ol]

Great video, thanks for the clear explanations!

[@sweetASrere]

I’m still not sure about why u said z test is crapy .. what if we have different measures for the same sample and each measure is on a different scale (for example a class of students scores on 3 math, reading and chemistry, and the scores are on different scales - out of 100, 75, and 90 respectively) isnt a z test here is crucial?

[@shariqanasreen4242]

Thanks for making it so simple

[@dibagabbary2066]

The best video on this topic. Thanks a lot

[@jikkukurien3004]

Thanks Kody buddy!

[@davidoconnor9167]

Wow.. so well explained, Thanks a bunch Kody!