Correlation Flashcards
correlation
assesses the degree to which scores on two variables are related
correlation coefficient (r)
index of the extent to which two variables are linearly correlated (strength)
Pearson’s Product-moment correlation coefficient (r)
used when there is a (1) linear monotonic relationship with no outliers and must be measured on (2) interval scales
report was the correlation significant? was the correlation positive/negative, weak/moderate/strong? what were the variables? r(N-2) = [r-value], p = [p-value] what does this suggest?
spearman’s rank correlation coefficient (rs)
monotonic but non linear (curved graph) or if there are outliers
non-monotonic (u-shaped) - different analysis
report
explain why Rs if being used (outliers, non-linear)
strength and direction of relationship
variables investigating
what test was used (spearman’s rank correlation coefficient)
rs(N-2) = [Rs-value], p = [p-value]
what does this suggest?
partial correlation
used when you want to control for a ‘third variable’
measured the strength of relationship whilst controlling for a third variable
report what kind of correlation analysis used? what is it measuring (strength between two variables - list variables) what was it controlling for? significance, direction and strength? r(df) = [r-value], p = [p-value] what does this suggest