correlations

Question 1

Pearsons product moment correlation assumptions

Answer 1

produces correlation coefficient r

assumptions- interval/ratio
normally distributed
no outliers/ extreme scores
should be related pairs (for every score on x each person should have a score on y)
a linear relationship between variables
homoscedasticity-plot a scatterplot to test this- how close are plots to the line

Question 2

correlation coefficient (r)

Answer 2

-1= when values of one variable increase the other decreases
+1= when values of one variable increase the other increase
0=no linear relationship

closer to 1 the stronger the correlation

Question 3

shared variance and unique variation

Answer 3

change the correlation decimal to% by square it

the other % is unique variance

Question 4

if the unique variance is lower than the shared variance what happens?

Answer 4

the r value (correlation coefficient) will be high

Question 5

Cohens effect sizes

Answer 5

large=+/- 0.5-1
medium=+/- 0.3-0.49
small=+/- 0.1-0.29

Question 6

what is partial correlation?

Answer 6

taking away the third variable issue- controlling for a third variable
zero order- 2 variables
first order- 3 variables