Correlation and regression Flashcards
What does correlation find?
line of best fit
How does correlation find line of best fit?
by minimising differences (residuals) between the data and the line
If r is above zero the correlation is…
positive
If r is below zero the correlation is…
negative
If r is closer to 1 or -1 the correlation is…
strong
If r is closer to 0 the correlation is…
weak
If r^2 is close to 1, the correlation explains…
a lot of variance
If r^2 is close to 0, the correlation explains…
only a little variance
r^2 is also known as?
Co-efficient of determination
Correlation or regression?
Describes multiple relationships?
Regression
Correlation or regression?
Describes single relationship?
correlation
Correlation or regression?
Describes directions of relationships?
Regression
Correlation or regression?
x and y are interchangeable
correlation
Correlation or regression?
Allows prediction
regression
How many independent variables does simple linear regression have?
One
How many independent variables does multiple linear regression have?
two
What do multiple predictor variables find in multiple regression?
the best fitting surface with relation to residuals
What can cause problems in correlation and regression?
Non-linear relationships
Which predictors do correlation and regression deal with?
categorical, ordinal and non-linear
