Correlations Flashcards
correlation coefficient
the statistic which provides a summary pf the relationship between two variables
correlation
an association between 2 events
scatter plot
most obvious way to summarise correlational data
what can a scatter plot help to determine
the direction and potential strength of the relationship and youll be able to see if there are any outliers
whats the most common correlation coefficient
pearsons correlation
what does the sign of a correlation coefficient indicate
the direction of the relationship
how does a strong relationship look on a scatterplot
points lie close to a line
how does a weak relationship look on a scatterplot
points are widely scattered
what coefficicent is a perfect correlation
1
what coefficient is no relationship
0
what does a correlation say about the causation of variables
correlation does not imply causation
how does sample size affect a correlation
a larger sample size leads to more certainty that the relationship is real
when to accept the null hypothesis
if the sample correlation is in the middle 96%
when to accept the alternative hypothesis
if the correlation is in the extreme 5% of correlations
what is the parametric test for a coefficient
pearsons r
