Regression Flashcards
What are the two common goals of regression?
- explanatory modelling
- predictive modelling
What is the main goal of regression?
identify and define the straight line that best represents the relationship between variables
What is linear regression?
a statistical technique where we model the best fitting straight line for a set of data
What is distance?
measures the amount of error (residual) between the line and the actual data
What is the least-squares solution?
aims to minimize error in prediction
What is the best-fitting regression line?
smallest SSresidual
What is the process of testing the significance of a regression equation?
analysis of regression
What happens during regression analysis?
the F ratio is used to assess the overall significance of linear regression model by comparing the fit of a full model to the fit of a reduced model
What is the numerator of the F-ratio?
MSregression which is the variance in the Y scores that is predicted by the regression equation
What does the MSregression measure?
measures systematic changes in Y that occur when the value of X increases or decreases
What is the denominator of the F-ratio?
MSresidual which is the unpredicted variance in the Y scores
What does the MSresidual measure?
measures the changes in Y that are independent of changes in X
What is R^2?
the proportion of variance in the dependent/outcome variable (Y) that can be explained by the independent/predictor variable (X)
What does SSresidual tell us?
how much of the variation in the DV our model did not explain
What does SStotal tell us?
how much variation there is in the dv
