PSYC 1010 Study Guide - Final Guide: Pearson Product-Moment Correlation Coefficient, Test Statistic, Statistical Hypothesis Testing
29 Jun 2018
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1010 Chapter 13: Correlation
•Correlation is a co-relation between two variables
•Correlation coefficient: is a statistic that quantifies a relation between two variables
Characteristic:
•Either positive or negative
•Falls between -1.00 & 1.00
•Stretch of the coefficient is not size
•Positive correction: both high or both low
•Negative correlation: two variables one with high score variable and other with low score
•Perfect positive correction= 1.00
•Perfect negative correlation= -1.00
•Not in range of 1 to -1 then its wrong
•0.00= no correlation
Correlation is not causation
Three possible reasons for this observed correction;
•1st; variable A (cheating) could cause variable B (poor grades)
•2nd; variable B (poor grades) could cause variable A (cheating)
•3rd; variable C (some other influence) could be causing the correlation between
variable A (cheating) and variable B (poor grades)
The Pearson Correlation Coefficient
•Pearson correction coefficient: a statistic that qualifies a linear relation between two scale
variables ( a single number is used to describe the direction and strength of the relation
between two variables with their overall pattern indicates straight {symbolized by r} )
•r describes the direction and the strength of an association between two variables
•Inferential statistic we rely on hypothesis test to determine whether the correlation
coefficient is significantly different from 0
Calculating the Pearson Correlation Coefficient
•Positive correlation results when a high score (above the mean) on one variable tend to
indicate a high score. Negative correlation results hen a hight score on one variable tends to
incite a low sore ( below the mean) on the other variable
•Two positive deviation or two negative = positively correlated
•One of each = negative correlated
