Amazing lecture, prof. Stevens. Thank you for sharing it with us!
@ssnevets2 жыл бұрын
It is my favorite chapter of the whole book and I do hope it inspires you to take that second or third course in statistics. Understanding cause and effect is what we are all trying to do as a large community of people fumbling around in the dark. Right?
@shireenrosario30756 жыл бұрын
Very educative and to the point ! Great job !!
@wasiarasheed139 Жыл бұрын
How you select 0.8 and 0.1 as in the above example, none of the equation have these slope. Please Explain.
@ssnevets Жыл бұрын
Hello Wasia. I didn't select these values. They were determined from multiple linear regression software applied to this data (which I didn't provide). If you are wondering, there is no way for you to determine these slopes from the video presentation. It is meant to be a demonstration of how simple (one variable) linear regression can be misleading and how multi-variable linear regression can make sense of it.
@goodlifealways17375 жыл бұрын
thank you so much for this great video. Awesome. However i have a question. I have noticed that the control variable added correlates with both the dependent and independent variables. Does it have to be that way or this will make the model multi-collinear?
@ssnevets5 жыл бұрын
Usually, there's some degree of collinearity between predictor variables. In this case, there is. If you want to predict who will win the election, you could probably get by with just the approval rating. If you want to know the effect of campaign spending on the election result, you definitely want both variables. It depends on the question you are trying to answer.
@ssnevets5 жыл бұрын
Hi Goodlife Always. It doesn't always work out that way but it does sometimes. If the predictor variables are not collinear then you have found two independent predictor variables (that's really good). Quite often though, the predictor variables are correlated and you have collinearity. There's nothing wrong with that but if they are strongly correlated, you may only need one of them to make accurate predictions and avoid over-fitting the model.
@valentinsarmagal5 жыл бұрын
perfect example and explanation
@catalinafdsfds58833 жыл бұрын
Thank you so much for this video!!!!
@nochese5 жыл бұрын
Don’t 0.8 and 0.1 have units associated? So one can’t directly compare their magnitudes? 0.8 % votes per % approval vs 0.1% votes per $1000 spending.
@ssnevets5 жыл бұрын
Indeed. You're right. I say spending is not as important as the approval rating but that is an overstatement. If you're an incumbent looking at re-election with a lot of money and a low approval rating, spending is a lot more important than the approval rating.