What is a (mathematical) model?

[@statquest]

Support StatQuest by buying my book The StatQuest Illustrated Guide to Machine Learning or a Study Guide or Merch!!! statquest.org/statquest-store/

[@Uynix1978]

I have been a modeler for 11 years. I really like your expression about "model is a relationship". Just want to add a bit of my point of view. To me, statistical model is a relationship derived from examining the data using statistical theories. The relationships from these models usually can not derive from a physical law. Whether or not the relationship is linear/nonlinear/exponential/log, they are all pure speculations based on data. There are also physical models, such as modeling the speed of a car according to its weight. These are also models but the relationships are derived from the physical laws (in this case, Newton). Also in engineering, there are lots of empirical models, where the relationships ranges from non-physical to semi-physical, such as Manning's equation. Part of the model can be explained by physics, but part of it is not. Just my two cents to share.

[@anthonyraj100]

Well said ! Thank you for the explanation !

[@benphua]

Thank you for your input Xinyu, that was very useful

[@TaoCui]

this is super helpful to clearly define the differences between a statistical model and a process-based model

[@guliyevshahriyar]

Thank you very much

[@makulmahato8663]

What is imerical?

[@Patrick_Bentolila]

To make things simple to understand without making them empty of their substance. This is the essence of being human, able to internalize things in such a way that sharing with others is like singing a song.

[@statquest]

Thanks!

[@serine-sg2li]

That's a nice way to say it!

[@developandplay]

Thank you for the great explanation. I have been learning all these complicated concepts evolving around MCMC. Only now have I realized that I wasn't completly sure what the term model was supposed to be in that context.

[@oscarrosalescorzo]

I love your content! It makes it so easy to understand topics that can be deeply technical. You are awesome!

[@statquest]

Wow, thank you!

[@harryliu1005]

This dude even explains what is model, he knows everything, Inifinite Bam for Him!!!!

[@statquest]

Thank you! :)

[@olanola4202]

Thank you so much for your lovely explanation. I was wondering about how to use models to come up with data and now I understand. Thanks.

[@perjoraxperj2115]

the dotted lines are not actually the distance from the model to the actual data points. the distance between a point and a line is the perpendicular drawn from the point up to that line

[@statquest]

There are lots of ways to define distance. See: en.wikipedia.org/wiki/Metric_(mathematics) So, in this case, distance is defined as the vertical distance.

[@dsd1610]

Your intro BGM makes me feel so comfortable. Triple Bam! haha

[@statquest]

:)

[@DanielSoll]

Thank you! I loved your work on GLM, would really appreciate it if you had a look at mixed models as well

[@statquest]

Thanks! I'll keep that in mind.

[@PRATIK1900]

So, in terms of machilne learning, can we say that the model is the hypothesis? Since a hypothesis is an equation that best represents/estimates the relationship between certain factors or features (eg mouse size and weight)

[@statquest]

Yes! A model is a type of hypothesis.

[@setarehbakhshi6047]

You are awesome❤❤❤❤❤❤ thank you for making Stat fun. Can you do videos on econometrics?

[@statquest]

Thanks! I'll keep that in mind.

[@churchillroo8125]

@@statquest how far are you working on econometrics?

[@anaswahid8520]

Sir make videos on (negative binomial,beta and gamma ) Distributions by covering their examples.

[@statquest]

OK. I'll add those to the to-do list.

[@anthonyraj100]

I love the introduction song ! nice bro well done for me it is very difficulty subject to understand but your approach was different ! God bless !

[@MehrshadGolesorkhi]

Can you please do a video on mixed models and how to interpret interactions?

[@statquest]

I want to do those videos in the fall - as soon as I'm done with neural networks and deep learning.

[@MehrshadGolesorkhi]

@@statquest DOUBLE BAM. Thank you

[@viduradias4646]

Thank you

[@statquest]

:)

[@santoshgujar5237]

Thank you, Sir, Take my hand, take my whole life too, nice song

[@statquest]

:)

[@amitabhjayaswal]

Good morning! At 2:37 you mention, 'sometimes, a model isn't a straight line.' Please elaborate. Thanks

[@statquest]

In that example, I show a model that describes the relationship between a drug dosage and hair growth. Up to a certain point, there is a linear relationship between dosage and growth - both go up together. However, after a certain dosage, hair growth tapers off and no longer increases - even if we continue to increase the dosage. So the model is curved - it starts out straight, and then tapers off. Does that make sense?

[@pal999]

It does, but does that mean the model is non-linear or still linear? @@statquest

[@sohamdhas8589]

@@pal999 non linear

[@tymothylim6550]

Great video! Thanks a lot!

[@statquest]

:)

[@fahadreda3060]

Another Great lesson , Thanks Josh

[@statquest]

Hooray! I'm glad you are enjoying so many of the videos.

[@fahadreda3060]

@@statquest I am a master student doing my research in machine learning and I need to refresh my math and statistics skills.. your channel helping me a lot in understanding.. until now I understood every video you made .. so glad I found your channel.. please keep up the good work.. thanks again

[@statquest]

Good luck with your masters work!

[@bobbyb4uall]

Hi Josh, thank you for the brilliant explanation...could u pls explain how did u derive the formula for mouse size = 0.1 + 0.8 mouse size?

[@statquest]

I used linear regression. I have a bunch of videos that explain linear regression. Here's the first one: kzbin.info/www/bejne/hpKpgZWYa5t3rrM

[@naveenkumarp7896]

Thanks for the simple explanation. What about the point number 2 at 3:16. Are there any explanations on it ?

[@statquest]

Yes! See: kzbin.info/www/bejne/pJyVdIR_idKSm9E

[@naveenkumarp7896]

@@statquest Thank you! That's another BAM video :) I like when you say Terminology alert! That helps us to pay more attention also to the term.

[@statquest]

@@naveenkumarp7896 Hooray! :)

[@JOSHII87]

Can you explain from where these two values of 0.1 and 0.8 came in the equation? Thanks.

[@statquest]

See: kzbin.info/www/bejne/hpKpgZWYa5t3rrM and kzbin.info/www/bejne/qXXZZZlqqJeGeJo

[@vcello6450]

Can you cover panel data and fixed effects?

[@statquest]

I'll keep it in mind.

[@vcello6450]

StatQuest with Josh Starmer BAM!!!

[@EdwardLawPhD]

Hi, I haven't recieved email about the code to get membership discount in your merchandise store.

[@statquest]

I'll make a post with the code later today.

[@chiragpalan9780]

Josh, Which book do you recommand for statistics for those who are looking for career in ML and data science. Specially which contains some use cases of statistics.

[@statquest]

Unfortunately I don't know of any good statistics books.

[@JohnMartin-jx1wz]

Try 'statistics in small doses'

[@phoebewatson5014]

How did you calculate the 0.1 and 0.8?

[@statquest]

It's fit using least squares. I have a video that explains how least squares works here: kzbin.info/www/bejne/hpKpgZWYa5t3rrM

[@PapiJack]

"All models are wrong, but some are useful"

[@statquest]

Noted

[@s1s2233]

I want my professor to watch this video.

[@statquest]

:)

[@pratimparashkalita7347]

You are the best!

[@statquest]

Thank you! :)

[@THEMATT222]

👍

[@statquest]

bam!

[@THEMATT222]

@@statquest 👍👍

[@Wisam_Saleem]

GREAT! Thanks a lot

[@luisfredyhuachacavargas3835]

who created the statistical model?

[@statquest]

Like in a "historical" sense? Or are you asking about something else?

[@neochoy]

Bam!

[@statquest]

:)

[@yechaleali4861]

Heollo, Dears Can you define,,,,Geospatial statistical modeling?

[@statquest]

Unfortunately I've never heard of it.

[@sanikumarpal2366]

TRIPLE BAMMM!!!!!!!!!!!!!!!!

[@statquest]

:)

[@jakobfredriksson2272]

Best intro-song I've heard. Well, almost. Ducktales (link below) might be better but just by the margin. Actually, in this song; instead of "Ducktales, wooho", "StatQuest, wooho!" would fit perfect. kzbin.info/www/bejne/fmrGnoN7bZ2UlZI

[@statquest]

Bam! :)

[@avi12]

Am I the only one who thought of a computer mouse and not an animal mouse?

[@statquest]

:)

[@nihalshukla7718]

can you provide me notes of total playlist? thanks for better explanation. you are the best.

[@statquest]

I have study guides available here: statquest.org/studyguides/ p.s. you don't need to ask the same question more than once on my channel. I read and respond to every comment.

[@keewonlee3787]

BAaaam!

[@statquest]

Hooray!!!

[@eliias888]

W

[@statquest]

?

[@eliias888]

@@statquest W video = Awesome video

[@statquest]

@@eliias888 Awesome!