ABSTRACT
One that is very widely reported is effect-size r, which is simply the Pearson corre-
lation coefficient (r) described in Sections 33 through 36. As stated in those sec-
tions, r indicates the direction and strength of a relationship between two variables
expressed on a scale that ranges from -1.00 to 1.00, where 0.00 indicates no rela-
tionship. Values ofr are interpreted by first squaring them (r). For instance, when
greater than 0.00 on a scale that extends to a maximum possible value of 1.00.
