A graph that shows the data from a correlational study. The two scores for each individual appear as a single point in the graph with the vertical position of the point corresponding to one score and the horizontal position corresponding to the other.
Correlation Coefficient
A statistical value that measures and describes the direction and degree of relationship between two variables. The sign (+/-) indicates the direction of the relationship. The numerical value (0.0 to 1.0) indicates the strength or consistency of the relationship. The type (Pearson or Spearman) indicates the form of the relationship.
Positive Relationships
The tendency for two variables to change in the same direction; as one variable increases, the other also tends to increase.
Negative Relationship
The tendency for two variables to change in opposite directions; increases in one variable tend to be accompanied by decreases in the other.
Pearson Correlation
A correlation used to evaluate linear relationships.
Spearman Correlation
A correlation used with ordinal data or to evaluate monotonic relationships.
Coefficient of Determination
The squared value of a correlation and measures the percentage of variability in one variable that is determined, or predicted, by its relationship with the other variable.
Statistical Significance of a Correlation
In a correlational study, the correlation in the sample is large enough that it is very unlikely to have been produced by random variation, but rather represents a real relationship in the population.
