COMM 2002 Lecture Notes - Explained Variation, Ordinal Data

• School: Carleton University
• Department: Communication Studies
• Course: COMM 2002
• Professor: Heather Pyman

Document Summary

The nature of the relationship: what is the direction of the relationship + or , how strong is the relationship. Cramer"s v: strength of relationship between two nominal variables of one nominal and one ordinal variable, coefficient between 0-1- no direction with nominal variables. Pre measures for interval data: the statistic used is pearson"s r often called the correlation coefficient. R tells us how closely correlated two interval level variables: pearson"s r is the strength measure of linear regression. Instead of using the mode or ordering of the pairs as we did with nominal and ordinal data, with interval data we can use the mean. R varies between -1 and +1: best understood by visualizing plotted data. Regression line: we never have a perfect correlation. If the data is spread out in a random pattern the vraiales are unrelated, but if there is a pattern it can be measured by drawing a regression line or best fit line.