correlation coefficient
A number that describes the type and the strength of the relationship present in a set of data
curvilinear relationship
A relationship in which the π scores change their direction of change as the π scores change; also called a curvilinear relationship
linear relationship
A relationship in which the π scores change their direction of change as the π scores change; also called a curvilinear relationship
negative linear relationship
A linear relationship in which the π scores tend to decrease as the
π scores increase
nonlinear relationship
A relationship in which the π scores change their direction of change as the π scores change; also called a curvilinear relationship
outlier
A data point that lies outside of the general pattern in a scatterplot; created by an unusual π or π score
Pearson correlation coefficient
The correlation coefficient that describes the linear relationship between two interval or ratio variables; symbolized by r
positive linear relationship
A linear relationship in which the π scores tend to increase as the π
scores increase
regression line
The line drawn through the long dimension of a scatterplot that best fits the center of the scatterplot, thereby visually summarizing the scatterplot and indicating the type of relationship that is present
restriction of range
In correlation, improper limitation of the range of scores obtained on one or both variables, leading to an underestimate of the strength of the relationship between the two variables
scatterplot
A graph of the individual data points from a set of πβπ pairs
Spearman rank-order correlation coefficient
The correlation coefficient that describes the linear relationship between pairs of ranked scores
strength of a relationship
The extent to which one value of π within a relationship is consistently associated with one and only one value of π ; also called the degree of association
type of relationship
The form of the correlation between the π scores and the π scores in a set of data, determined by the overall direction in which the π scores change as the π scores change
