Correlation and Simple Regression - Part 1

Covariance shows

The degree to which 2 variable move (vary) together placed on an unstandardized scale

same direction:_____, opposite direction:_____, don’t move together: _____

positive, negative, 0

Covariance is

scale-dependent (only us in calculation)

Covariance ranges from

infinity to negative infinity

Correlation shows

The degree to which 2 variable move (vary) together placed on a standardized scale

Correlation is

not scale-dependent (researcher report this in a study)

Correlation ranges from

-1 to +1

2 relationships can have the same correlation, but

not the same covariance

Simple regression is

a method used to predict one variable (Y) from one other variable (X) by fitting a straight-line relationship between them

It’s “simple” bc

only use 1 predictor X

Equation of simple regression is

y = b0 + b1*X + e

bo is

intercept

intercept is

value of Y (outcome), when X is equal 0

b1 is

slope

slope is

how much Y changes when X is increases by 1

e is

residual

residual is

a part of Y the model can’t explain using X (account for error, difference between the actual value and the predicted value)