13. Assessing Relationships 3 Flashcards
What does goodness of fit compare?
- regression model
- mean
What does goodness of fit use?
SS_T, SS_R, SS_M
goodness of fit denoted by
R^2
What is R^2 a good gauge of?
size of relationship/prediction
What is also provided with a regression analysis?
f-stat
significant f-stat in a regression
means regression model is a good fit
f-stat and goodness of fit
measures how much the model has improved the prediction of the outcome compared to inaccuracy of the model
b_1 (slope) represents
change in outcome resulting from a unit of change in the predictor
if a regression coefficient is 0:
- unit of change in the predictor variable results in no change in predicted outcome
- regression line is flat
What is used to test the null hypothesis that the value of b is 0
t-stat
When is a multiple regression used?
when there are more than 1 continuous predictor variables (IVs)
steps to a multiple regression model
same as simple regression
methods of entering IVs for multiple regression
- hierarchical
- forced entry
- stepwise
- examiner decides order of entering predictors into model based on previous research
- most important predictor entered first
hierarchical
all predictor variables entered simultaneously into the model
forced entry
