Chapter 13 Quiz Flashcards
approach which combines multiple supervised models into a supermodel
ensemble
what will averaging multiple models yield?
a more precise answer than found individually
four ways to make ensembles
simple averaging or voting
combining predictions (median)
combining classifications
combining propensities
generate multiple random samples, run algorithm on each same and produce scores
bagging
fit model to data, draw sample with misclassified records that have a higher probability of selection, fit model to new sample
boosting
generating rank-ordered list of candidate models with automatic parameter tuning
automated machine learning
what does creating an ensemble do?
reduces the root mean squared error
what is the relationship between bias, variance, covariance, and correlation
bias <– variance <— covariance
covariance affects correlation
advantages of ensembles
more precise (especially for low/negative correlations)
weaknesses of ensembles
uncorrelated samples result in uncorrelated predictions
computational resources
blackbox model
advantages of AutoML
good starting point that can be tweaked to speed up analysis
weaknesses of AutoML
do not understand business problem/dataset