Week 5 - Multiple Regression Flashcards
What is hierachical regression?
Predictors are selected based on past work and the researcher decided in which order to enter the predictors into the model.
What are stepwise regressions?
Decisions about the order in which predictors are entered into the model are based on a purely mathematical criterion.
What is forward selection?
An initial model is defined that contains only the constant (b0). The computer then searches for the predictor that best predicts the outcome variable by selecting the predictor that has the highest simple correlation with the outcome.
What is backward selection?
The computer begins by placing all the predictors in the model and then calculating the contribution of each one by looking at the significance value of the t-test for each predictor.
What is multiple regression?
When there is more than one explanatory variable.
What is linear regression?
A linear approach to modelling the relationship betwen a dependent variable and an independent variable. When one explanatory variable is involved it is called simple linear regression.
What is multivariate linerar regression?
This is where multiple correlated dependent variables are predicted.
What are supressor effects?
These occur when a predictor has a significant effect but only when another variable is held constant.
What is the akaike information criterion?
It’s a measure of fit which penalises the model for having more variables. When a model is used, the representation will almost never be exact so some information will be lost using the model to represent the process. The AIC estimates the relative amount of information lost by a given model. The less information a model loses, the better the quality of model.
What is R2?
The coefficient of determination. That is the proportion of the variance in the dependent variable that that is predictable from the independent variable.
