Psychology 2820E Lecture Notes - Lecture 12: Scatter Plot, Experiment, Negative Relationship

• School: Western University
• Department: Psychology
• Course: Psychology 2820E
• Professor: Riley Hinson

Document Summary

The relationship between variables is important for several reasons: correlation is a necessary condition for causation. In many situations involving real life behaviour it is not possible to meet the conditions necessary to perform a true experiment. If some variable is related to the behaviour of interest it is possible to use statistical procedures to make predictions. Positive relationship: one may increase as the other increases. Negative relationship: one may decrease as the other increases. Correlation coefficient: the degree of the relationship between two variables (assumes values between +1. 0 and -1. 0) The further the correlation coefficient is from zero, and the closer it is to either +1. 0 or - 1. 0, the stronger the relationship between the two variables. A perfect correlation exists at either +1. 0 or -1. 0. In a perfect correlation, each occurrence of a particular value of x is always associated with the same value of y. A scatter plot visually presents bivariate data.