Box Plots in R with t-test, Mann-Whitney, ANOVA, Kruskal-Wallis, Shapiro-Wilk, Levene and post-hocs

Hi, this video builds on the previous one - Box-plots with statistical details, so I highly recommend to check it out first: • Box-Plots with Statist...
In this video you'll learn how to conduct the most important statistical tests and visualise them on top of informative box-violin-plots in a simple intuitive R syntax. Particularly, you’ll learn how to do Student’s and Welsh’ t-tests, Mann-Whitney, Fisher’s and Welsh ANOVA and Kruskal-Wallis tests … like the one you see on the screen… You’ll also learn how to choose a correct test via checking assumptions in R with Shapiro-Wilk normality test and Levene’s homogeneity of variances test. Last, but not least you’ll be able to get a correct post-hoc analysis for ANOVA and Kruskal Wallis with p-values corrected for multiple comparisons. If you don’t know what post-hoc and p-value corrections are, no worries, I’ll briefly explain it. So, this video is not only about simple R code, but also about learning statistics by doing. Let’s get right into it!
Don't hesitate to use english subtitles, I edited them.
If you only want the code (or want to support me), consider join the channel (join button below any of the videos), because I provide the code upon members requests.
I also created a quick demo in R in the next video.
Enjoy! 🥳

[@WilOspinoC]

This comes from an outer level. THis is great. Thanks!!!

[@yuzaR-Data-Science]

You're very welcome! I later actually produced a separate video for every test ggstatslot does. For example, you can check out t-test, or kruskal-wallis, or chi-square, or correlation ... any common statistical test.

[@WilOspinoC]

@@yuzaR-Data-Science I am going to check them. Now I am really digesting the statistical information.

[@VladimirShatalov]

Nice presentation, thank you!

[@yuzaR-Data-Science]

Thanks for a nice feedback, Vladimir! I am glad it is useful!

[@chacmool2581]

Awesome stuff. As always.
I want a vid from you on ElasticNet and how it can supplant Ridge/Lasso.

[@yuzaR-Data-Science]

Great suggestion! The machine learning stuff is coming anyway. But it'll take some time. I just need to cover some basic .... and get more time from my day job. Year, similar to the tests, I wanna cover every useful model. Ideally :)

[@chacmool2581]

@@yuzaR-Data-Science MARS is interesting too. Does feature selection/reduction and is kinda interpretable.

[@yuzaR-Data-Science]

Oh, that's another good one I have to dive into to be able to answer. We'll get there ;)

[@jarade815]

thanks you very much to teach

[@yuzaR-Data-Science]

Thanks for watching

[@cristianlizarazo8016]

excelente video gracias

[@yuzaR-Data-Science]

de nada amigo

[@AngelFelizF]

Excelent.
Thanks.

[@yuzaR-Data-Science]

Glad you like it!

[@bogdanandjelic2200]

good work man, any chance of advising me? got some data...Kinda want more than Wilcoxon from SPSS

[@yuzaR-Data-Science]

Thanks for the feedback, mate! Check out my later videos and blog-post (links to blogs are always below the video in the description). You’ll get many ideas. Unfortunately I can’t advise folks, have two day jobs and making videos on top of it. But I totally recommend you to switch from SPSS to R

[@bogdanandjelic2200]

@@yuzaR-Data-Science I just need to know how do I swap places of two variables (boxes) on the plot. After on the left, makes no sense... Thanks.

[@bogdanandjelic2200]

@@yuzaR-Data-Science Also, where do we find SD

[@yuzaR-Data-Science]

No worries, mate, you just need to change the levels of a factor variable "test" in your data:
Fitness %>%
mutate(test = factor(test, levels = c("Before", "After")))
the test will use the order you define in your data

[@yuzaR-Data-Science]

you mean standard deviation of every group? well, there is an amazing function "describe" from {dlookr} package. It gives you all the stats for your groups in one word. it works perfectly with "tidyverse", thats how you can use "group_by()". I also did a video on dlookr, there are more useful things then just "describe"

[@danylokravchuk]

Sadly, but notch is not accessible now

[@yuzaR-Data-Science]

Yeah, I asked the author of the package about it, and here is what he said: "I removed notch because it often just collapses on itself (mathworks.com/matlabcentral/answers/461791-what-do-lines-that-double-back-on-themselves-mean-box-plots)- Additionally, it is typically used for significance testing, which is redundant because ggstatsplot already provides such details in the plot itself."

[@danylokravchuk]

@@yuzaR-Data-Science Thank you for your answer.

[@yuzaR-Data-Science]

You are welcome!