logistic regression

Question 1

what is logistic regression

Answer 1

a model that outputs real number in [0,1] thresholded at 0.5 to obtain primary outcomes (class 0 or class 1)

Question 2

what is the goal of logisitic regression

Answer 2

predict probability example belongs to the ‘1’ class

Question 3

applications of log reg

Answer 3

used in medical and social sciences

Question 4

appoarch of log reg

Answer 4

1) used log odds to create a linear model
2) appply sigmoid function to convert log odds to a real number in [0,1] i.e the probability

Question 5

what does probability mean

Answer 5

A number p ∈ [0,1] that describes likelihood of event occurring

Question 6

what does odds mean

Answer 6

ratio of the probabilty of the event occurring to the probability of the event not occurring

Question 7

what does logit (log odds) mean

Answer 7

the logarithms of the odds

Question 8

what is the equation for log-odds

Answer 8

logit(p) = log (p / 1 - p) =log(p) - log(1 -p)