Regression Flashcards
(45 cards)
Multivariate Designs
A study designed to test an association Involving more than two measured variables.
What are the 3 criteria to establish causation?
Covariance
Temporal Precedence
Internal Validity; third variables
Linear Regression
The model that estimates the relationship/ preidcted relationship between two variables.
When is linear regression appropriate?
when you want to predict a continuous outcome based on one or more predictor variables.
When can you use linear regression?
- When the relationship between X and Y is linear
- When variables are quantitative
What are the two parts of linear regression?
a= Intercept
b1= slope
What does the intercept of linear regression mean?
The predicted score for someone who ___ for 0 ____.
What does the slope of linear regression mean?
The amount Y changes when X increases by 1 unit.
What 3 things are used to assess the model of fit for linear regression?
- Sum of Squares
- Root Mean Squared Error (RMSE)
- R-Squared (R^2)
Sum of Squares of Y given X
Measures the total squared differences between observed Y and predicted Y.
What value of sum of squares indicates a better model fit?
A smaller sum
RMSE (Root Mean Squared Error)
The typical size of prediction errors.
What value of RMSE indicates a better model fit for linear regression?
A smaller value
What units are RMSE in?
The same units as Y
R-Squared (R^2)
Proportion of variance in Y explained by X.
If R^2 = 0.25, what does that mean?
25% of variance in ___ is explained by ___ variability.
Longitudinal Design
A study in which the same variables are measured in the same people at different points in time.
What can longitudinal designs provide evidence for?
Temporal Precedence
What can longitudinal designs be adapted to do?
Test causal claims
Cross Sectional Correlations
A correlation between two variables that are measured at the same time.
What can cross sectional correlations not measure?
Temporal precedence
Autocorrelations
The correlation of one variable with itself, measured at two different times.
Cross-Lag Correlations
A correlation between an earlier measure of one variable and a later measure of another variable.
What are cross lag correlations considered?
The primary interest of researchers
- address directionality and establish temporal precedence