[ WEEK 1 STATS ] CORRELATION ANALYSIS

• BIVARIATE DATA - The purpose of analysis is to describe the relationship between the two variables in terms of strength and direction.
• CORRELATION ANALYSIS - A statistical method used to determine whether a relationship between two variables exist.
• SCATTERPLOT - A graph of ordered pairs of data values that is used to determine if a relationship exists between two variables.
• LINE OF BEST FIT (TREND LINE OR REGRESSION LINE) - The line that best expresses the relationship between points in a scatterplot which indicates the direction of the slope.
• POSITIVE CORRELATION - As one variable increases so does the other variable.
• NEGATIVE CORRELATION - As one variable increases the other variable decreases.
• NO CORRELATION - There is no relationship between the two variables.
• PERFECT POSITIVE CORRELATION - When one variable changes, the other variables change in the same direction.
• PERFECT NEGATIVE CORRELATION - When one variable changes, the other variables change in the opposite direction.
• PEARSON PRODUCT-MOMENT CORRELATION COEFFICIENT - Measures the strength and direction of association that exists between two variables. The direction of correlation is indicated by the sign of r, while its strength is indicated by the absolute value of r.
• 1 - perfect positive

  0.9 - strong positive

  0.5 - weak positive

  0 - no correlation

  -0.5 - weak negative

  -0.9 - strong negative

  -1 - perfect negative