Lecture 7 Chapter 8 Flashcards
What does the correlation coefficients tell us?
Tell us about the strength and direction of the linear relationship between 2 variables.
What is the range for correlation coefficients?
Can range from -1.00 to +1.00
What range has a strong relationship
close to -1or+1
or closer to 0
close to -1or+1
what is a ‘perfect’ linear relationship?
When one variable changes by one unit, so does the other.
Does effect size translate into an actual clinical or practical significance?
no
What is the definition of regression analysis?
Used for predicting dependent variables from other independent variables. We wouldn’t want to try to predict a variable from another if the variables weren’t related/correlated. Correlation and regression analysis thus go hand in hand.
what is a simple linear regression?
Simple linear regression tries to predict one dependent variable from one independent variable using the formula for one of the lines of best fit through a scatterplot of the variables.
DV must be scale (continuous) level of measurement.
What measurement does the DV have to be for a simple linear regression?
DV must be scale (continuous) level of measurement.
what is multiple linear regression?
Multiple linear regression tries to predict one dependent variable from two or more independent variables using the formula for one of the lines of best fit through a multi-dimensional scatterplot of all the variables.
What measurement does the DV have to be for a multiple linear regression?
DV must be scale (continuous) level of measurement.
For a simple linear regression, what is the formula name that is used?
Line of best fit
What is the regression equation?
Ŷ = bX + a
In the regression equation, what is the Ŷ?
Ŷ = variable being predicted (the DV)
In the regression equation, what is the X?
X = variable being used to make the prediction (the IV)
In the regression equation, what is the b?
b = the ‘slope” of the line, or how ‘steep’ it is (rise over run; change in Y per unit change in X). It is the ‘regression coefficient’