Conditional Probability

MIT RES.TLL-004 Concept Vignettes
Instructor: Sam Watson

This video provides an introduction to conditional probability and its calculations, as well as how it can be used to interpret medical diagnoses.

License: Creative Commons BY-NC-SA

[grequchannel]

I watched this video about 5 times with brakes for exercises and finally understand! Great, thanks!!

[antonioclemente]

that moment wen hours of study are cleared by a 12 minute video no wonder the MIT is number one wish i had 200k to spend in that college unfortunatelly poor scores and have no money... the bright side is that i can calculate the probs of getting there anyway thanks MIT

[mohammedlabeeb]

Amazing video. I have watched so many long videos about conditional probability.
This video is very dense, clear, and right on the point. I am going to watch the rest of the videos through this channel

[TheRealGinaCharles]

I spent over 5 days trying to figure out the given term. You are amazing! I finally under the conditional Probability. Thank you.

[zhenminliu]

This is a succinct and elucidatory video. The table and tree approaches are particularly useful for an old person like me who find it hard to keep things in our short term memory. An excellent video for me. Thank you!

[pseudovictim]

No distraction...Check!
Clear explanations ...Check!
No memorisation required...Check!
Clear demonstrations...Check!
Excellent!

[syremusic_]

That could not have been any clearer. Thank you MIT and thank you Sam.

[kdub]

This is absolutely the clearest explanation of conditional probability I have ever seen.

[RobvanMechelen]

Sam, you are a great teacher!
Sample space is explained excellently, just by visualising.
The cancer example emphazises that one should take the prevalence of cancer into account, interpretating the quality of a test positive result in patients who do not have the disease.
I have never seen explaining the subject of conditional probability, so clearly,

[sau]

the concept of tree diagrams makes it so easy to visualize. Thank you

[MH-ocde]

The video seems to have cut off the last number (.01) in the numerator of the caclulation of P(cancer | test +) at 10:58

[tsunamio]

This is an excellent course! The only thing that I could point is that at 7:30, it would have be better to use different outcomes for P(B1 and Y2), P(Y1 and B2) and P(Y1 and Y2). 3/10 for each can be a bit confusing, especially at 8:22.

[vbond]

Sam Watson, start your own Youtube channel! This is so easy to understand! Finally my marbles fell in the right places :p

[leitawilliams]

Cool video, never knew about the tree diagram before this. Very useful in finding out the probability of the same thing twice.

[arnoldbirkenhager]

Great vid! Just a caveat for the viewers about the medical tests. He forgot to mention he was specifically talking about screening tests for rare but horrible diseases in the general population. Normally when your doctor orders a test, your prior probability is a lot higher than the prevalence in the general population. Let's say because you have symptoms fitting the disease, your prior is 1 in 10 instead of 1 in 1000. Now the test is suddenly very useful. By testing positive, you go from 10% to 92% probability of having the disease.

[macbobXD]

Oh my god you have cleared my mind here !!! :D

[dangakong]

Sets and Probability is the basics of flexible thinking and reasoning. What a topic

[joaopaulo]

This lesson is amazing! It's something every person should know about it because it gives you the ability to call the correct decision for your life, despite the matter is an illness or not.

[vw_insidevillage]

Excellent teaching.. easiest way to solve conditional problem

[Legendnewer]

My lecturer *for this subject* isn’t bad at explanation, but this is so easy to learn and understand