Funny that the example was sleep deprivation, because I fell asleep during the lectures on main effects and interactions and missed learning this. Thank you so much for helping me out!

The easiest to understand explanation of all the different videos i have looked at. Perfect! Thank you!

For a now retired but still active biomedical scientist this is the best explanation I've ever seen of main effects and interaction

amazing explanation, thanks boss

Oh my goodness! I finally get it! Thank you so much for making this topic so understandable.

Hi Jim, thank you for your simplified version of understanding fANOVA! Choosing the right statistical test gets quite difficult with many groups, and multi-dimensional output variables, this helped a lot!

This is so great! Thank you for providing this to your students and the rest of the students in need of an explanation.

Excellent video. Searching on KZfaq for the last hour or so for a clear explanation on the meaning of main effects and interaction and this video was the best by far.

Oh my GOODNESS thank you so much for this. My discussion went over it so quickly I didn't catch any of it! Thank you a thousand times over

After reading text books , reading so many articles and research paper and seeing many youtube videos I thought of giving up the topic but at last I found your video and it made the concept all clear. Thanks a lot from India for uploading such nice video on this complex topic.

After a day of trying to figure this out in my textbook, I finally looked it up on KZfaq. You just resolved a days worth of stress. Fuck the textbook. I’m using KZfaq from now on.

I'm currently in a research methods class and this video has really helped me figure out main effects. My teacher gave us an exam including main effects and didn't explain at all like you did. Thank you.

Thank you for this video!!! I was tied up in knots over my main effects and interactions as there was significant main effects but not interactions. Made perfect sense. Funny how you can spend 3years at uni being lost in statistics, yet a simple video works wonders :-D Thank you!

This is a super helpful explanation to a relatively complex topic, it makes it seem very intuitive and I wanted to thank the author of this video

Most helpful. The best explanation I've seen on this. Thank you.

This is the video that helped my brain wrap around the topic main effect and interaction. Thank very much !

the vid my professor attached to teach us this cuz it's an online class is 2 hours long. You just summed up 2 hours, held my attention, and made it make sense. omg THANK YOU!!!!!! - a sleep deprived nursing student who's trying to self teach herself stats

Thank you! This made absolutely no sense before, and I just got a perfect score on a test after I listened to this! :)

AMAZING VIDEO. you're saving lives, my friend!

Thank you so much Jim. That really made it clear. You have a superb way of explaining things.

I go to school in the U.S. and was so confused learning about this, but this video helped me understand factorial designs better, thank you!

This was a great explanation, especially describing how to interpret the line graph! Thanks!!

You have hit the bull's eye. Crystal clear explanation. Salute

Thank you Jim for this simple explanation about the two topics. At min. 6:30 (about interaction) I suggest to note the difference on 1h and 24h of caffeine on the percent correct/ y-line.. The difference of 10 (percent) is on the y-line/vertical line. Regards and keep this up!

Most useful exploration of this I have read or seen - thank you

I put this video in my pocket! Awesome and clearly to the point thank you!

This is great, it really helped me understand main effect and interaction. Thank you!

Been stuck on this in 2 days, this video cleared everything up. Thank you Jim!

I am having my very last exam of my whole study in 2 hours and this topic was something I just could not wrap my head around. Now it finally make sense to me. (And it is so ironically that I am sleep deprived and only working on caffeine fuel). Thank you!

This sleep deprived Tilburg University student thanks you very much! Great explanation and very useful for my research note.

THANK YOU THANK YOU THANK YOUUUUUUUUUUU!!! Sorry for the caps, but I've never seen SUCH A CLEAR explanation of this. THANK YOU!

AMAZING! Thank you so much for this!

Awesome job Jim! I only spent one whole week trying to understand anything at all about main and interaction effect, banging my head and hoping I could drill it in (thanks to a no-so-good UC Berkeley PhD psych teacher), and then you happened in my life!! (and this is a junior college psych class!!). Thank you!!!

this makes so much more sense now, thanks!

thank you - just completing the last assignment of my Research Methods in Education / online and this helped a lot Jim ! Cheers fro NZ :D

I'm not even from this uni and I wish you were one of my lectures 😔

Very helpful video. Thank you for taking the time to post it and make it public.

Thank you very much for your explanation!!! This video really helps me understand better about main effects and interactions!!!

holy cow, you made that so easy to understand! i can't believe none of my teachers could explain it so simply! thank you so much! research methods has been the bane of my existence because i just can't seem to process it!

I hope you all find this video useful! If you have any questions, please do drop me an email. And if the video has REALLY helped and you want to buy me a beer, please see www.paypal.com/donate/?hosted_button_id=L692FVF8PNUKU

That was the best video about this topic. Thanks a lot!

My lecturer would not stop going on tangents and then pausing only to attempt three more times to explain what these effects are. My test is tomorrow, you are a life saver. Thank you!

Thank you very much Jim. It help me a great deal.

This video helped clear things up. Thank you so much!

Thank you this is so much more clear than the mess my lecturer left me with!!

Thank you! Such a great and clear explanation!

Thanks for making it short, sweet, and to the point! I wish my minister would do the same in church!

this was beautifully described and the example was easy to interpret! thanks!!

Clear explanation. This helps me a lot! Thank you~~

Amazing video! Very well explained, thank you. Do you have another video where you explain how to test whether these effects are significant or not? Would be greatly appreciated!

Very simple to understand the complex concept, thank you very much

Thank you Jim! I appreciate this :)

This was super useful! Thanks a bunch!

Thank you sooooo much for this video!! My GPA has been saved.

This has helped me a lot, thank you! (:

WISH YOU WERE MY LECTURER

Thanks! You really helped me understand this better.

Thank you so much! You just saved me for finals :')! Please keep uploading, you explain things perfectly :D

what was the value of the interaction? I understand that the change in the caffeine pill sample was small, 10, and the change in the placebo was great, 75, so does this make the interaction effect 65? thanks :)

Thank you! This might have saved me

best explanation on this topic .Thank you.

So clear to understand, thanks you so much!!!

Thank you so much, this really explained things clearly.

Really great vid!!!

What a great video! I appreciate it so much, I wonder if you can go into describing the kind of interactions there are and the qualitative and quantitative aspects of an interaction? I see that they are diverging but it's hard for me to understand what that means. Would this be a quantitative interaction because caffeine strengthens the other Independent variable? (Behavioral Stats Exam coming up this week) Thank you again!

This is great and it helped me a lot! Thank you!

Thank you so much Jim!

Thank you sir for making sense of this topic :)

Great explanation. Thank you.

Really good explaining!

having exam about these atm and its so great that i found this video, thank you so much mate :)

Thank you!!! This was so helpful. Please keep posting videos!

Well explained, thanks!

This helped so much to see it in a real example. My lecturer showed them as A and B so I had no idea what was happening

excellent. well simplified. i have clearly understood

Very clear !!! Thanks 😊

Extremely Helpful!!!

This was an awesome video, thank you for your help.

Thank you for the great explanation

Nice examples. Thanks.

Very clear explanation--thanks, sir.

I have an exam tomorrow for my research methods class, thank you for this video!

great explanation ,thank you

Great video, thanks.

Thanks for this video. It is easy to understand.

this helped me so much!! thank you

Thank you very much Helped a lot!

Super thank you for doing this. Helped me out a ton. :)

Nice illustration mate!

this was soo clear :)

much respect, i am now more prepared for my final tomorrow

Very helpful, thanks a lot!

yes jim mate sick vid helped me and my m8 a lot with some well hard stats work that she couldnt do safe again xx

really good explanation, thanks.

thanks for the simple clarification

very clear, very nice :) Ty!

Thank you,it’s very useful!

best video on the subject

U were much useful. Thankyou ❤😊