B07 Logistic Regression Flashcards
Exam Prep
Regression
Machine learning technique where the goal is to model
the ____ and ____ of numeric relationships in order
to predict a target variable based on the values of
previously observed explanatory variables.
Size and Strength
Popular regression techniques include:
Linear Regression
Logistic Regression
Poisson Regression (log-linear)
Linear Regression:
The goal is to estimate the values for ___ and __ in order
to minimize _____________________________
between the actual and predicted values.
B0 and B1 (Beta)
The sum of squared errors
Limits of Linear Regression
- requires a normal distribution of the response variable
- decision boundary
In logistic regression, the coefficients are estimated
using a technique called __________________
Maximum Likelihood
Estimation (MLE)
Unlike the _________________ method
used by linear regression, finding a closed form for
the coefficients using MLE is not possible. Instead, the
process is iterative.
Ordinary Least Squares (OLS)
The ___________________________is an extension of
linear regression that allows for linear predictors to be
related to a response variable that is not normally
distributed by using a transformation or link function
Generalized Linear Model (GLM)
The link function used for binomial logistic regression is called the _________
logit function
In Logistic Regression
For every unit increase in
tumor size, the odds of it
being malignant changes
by a multiple of ___
e^Beta
If B<0 , the odds that the tumor is malignant \_\_\_\_\_\_\_ as tumor size increases. If B>0, the odds that the tumor is malignant \_\_\_\_\_\_\_\_ as tumor size increases.
decreases
increases
An estimate of the relative information lost by a given
model: the less information a model loses, the higher
the quality of the model
Akaike Information Criterion (AIC)
Strengths of Logistic Regression?
-Outputs have a nice probabilistic interpretation. -Can be regularized to avoid overfitting. -Easy to implement and use. -Very efficient to train.
Weaknesses of Logistic Regression?
-Makes strong assumptions about the data. -Does not do well with missing data. -Tends to underperform when there are multiple or non-linear decision boundaries. -Does not naturally capture complex relationships.