PSYC 2021 Lecture Notes - Lecture 15: Scatter Plot, Pearson Product-Moment Correlation Coefficient, Repeated Measures Design
7 Feb 2018
School
Department
Course
Professor
Document Summary
A correlation is a numerical value that describes and measures three characteristics of the relationship between x and y: the direction of the relationship: Should have a linear relationship; the points in the scatter plot tend to cluster around a straight line. We have drawn a line through the middle of the data points in each figure to help show the relationship. Most common use of correlation: to measure straight-line relationships: the strength or consistency of the relationship. Indicates a perfectly consistent relationship: a correlation of 0 indicates no consistency, the data points are scattered randomly with no clear trend. Intermediate values between 0 and 1 indicated the degree of consistency. A negative value for correlation indicates: increases in x tend to be accompanied by decreases in y. Measures the degree and the direction of the linear relationship between two variables. Corresponding correlation for the entire population is identified by the greek letter rho.
