What is the Correlation Method - Essay Example

The correlation method uses variables to establish a statistical relationship between the two variables. One example would be the correlation, or link, between eating habits and childhood obesity. However, correlation does not equal causation: “The most a researcher can state about 2 variables that correlate is that they relate to one another.”

How the correlation method is conducted.
The correlation method is conducted using a mathematical equation to estimate two variables and their relationship. The variables range from +1.0 to -1.0. The strength h is determined by the value of “r”. Whether + or -, the closer to 1, the stronger the relationship.

Inaccurate estimates can occur using the correlation method: “Accordingly, some modes of analysis of longitudinal data (e.g., the difference score method, the partial correlation method, and the semi-partial correlation method) may sometimes yield inaccurate estimates of the association between variables, even results that are the inverse of predictions.”
Other factors that may affect the correlation method are variables that aren’t included in the research. The left-out variables may affect the outcome.

An example of research using the correlation method with children.
A study of the long-term effects of childcare was performed on children from 4 and a half years until the end of the 6th grade. The study was conducted at the National Institute of Child Health and Human Development. The results indicated that: “Parenting was a stronger and more consistent predictor of children's development than early child-care experience, higher quality care predicted higher vocabulary scores, and more exposure to center care predicted more teacher-reported externalizing problems.”

In a study on peer interaction, 81 children from 1 classroom each of kindergarten, first, second, and third grades were ranked on measures of popularity, cognitive and social development. From this study, “Popularity was found to be closely related to social development, but its relations to measures of physical concept development were relatively minor.”

A negative correlation.
A negative correlation is less than zero but greater than or equal to -1. When the variables move in opposite directions, there is a negative correlation.
Schaefer says, “An analysis of data reported by Kennedy, Van de Riet, and White suggests that their finding of a significant negative correlation of mean IQ with age for southeastern Negro children was produced by the sampling method.”

The negative correlation is derived from: “The interpretation that a low mean IQ developed during the preschool years and remained stable during the elementary-school years suggests a need for research on factors related to intellectual development in the preschool years and for preschool programs designed to raise the level of intellectual functioning of culturally deprived children.”

A positive correlation.
A positive correlation is greater than zero but less than or equal to 1. When the variables increase or decrease together, there is a positive correlation.