Creswell (2008) defines a correlation as "a statistical test to determine the tendency or pattern for two (or more) variables or two sets of data to vary consistently" (p. 638).
Georgiou, G. K., Parrila, R., Kirby, J. R., & Stephenson, K. (2008). Rapid naming components and their relationship with phonological awareness, orthographic knowledge, speed of processing, and different reading outcomes. Scientific Studies of Reading, 12, 325-350.
Abstract [with notes added in red]:
This study examines (a) how rapid automatized naming (RAN) speed components—articulation time and pause time—predict [key word] reading accuracy and reading fluency in Grades 2 and 3, and (b) how RAN components are related to [key words] measures of phonological awareness, orthographic knowledge, and speed of processing. Forty-eight children were administered RAN tasks in Grades 1, 2, and 3. Results indicated that pause time was highly correlated with both reading accuracy and reading fluency measures and shared more of its predictive variance with orthographic knowledge than with phonological awareness or speed of processing. In contrast, articulation time was only weakly correlated with the reading measures and was rather independent from any processing skill at any point of measurement.
Here is one correlation table from this study: