Week 8 - Introduction to Regression Analysis Flashcards
What does ‘Covariance’ measure?
measures the strength of the linear relationship between 2 numerical values.
What does the ‘Coefficient of Covariance’ measure?
measures the relative strength of the linear relationship between two numerical variables.
What is a ‘Scatter Diagram’?
Graphical representation of the relationship between two numerical variables; plotted points represent the given values of the independent variable and corresponding dependent variable.
Fill in the following one-word gap: The Response variable is the _______ variable.
dependent
Fill in the following one-word gap: The Explanatory variable is the _______ variable.
independent
What is the ‘Prediction line’?
The straight line derived by a regression equation using the method of least squares.
What is the ‘Regression coefficients’?
The calculated parameters in regression that specify the interval and slope of the linear line defining the relationship between the independent and dependent variables.
Define ‘Total variation’?
The sum of the squared differences between each value and the grand mean.
What is the ‘Regression sum of squares (SSR)’?
The degree of variation between X and Y variables that is explained by the defined regression relationship between the two variables. Specifically, the degree of variation in the Y variable that is accounted for by variation in the X variable(s).
Define ‘Linearity’?
The assumption that the relationship between variables is linear.
Define ‘Normaility’?
An assumption that the errors in a regression are normally distributed at each value of X.
Define ‘Equal variance (homoscedasticity)’?
An assumption that the variance of the error terms is constant for all values of X.
What is the ‘Net regression coefficient’?
The population slope coefficient representing the change in the mean of Y per unit change in X, taking into account the effect of other independent X variables in a multiple regression.
