PSYC 3380 Lecture Notes - Lecture 5: Partial Correlation, Standard Score, Pearson Product-Moment Correlation Coefficient

• School: University of Guelph
• Department: Psychology
• Course: PSYC 3380
• Professor: Jeffrey Spence

Document Summary

A standardized variable has been transformed so that its mean is 0 and standard deviation is 1 (variance is 1 too) Most common way to standardize is to convert raw scores to z-scores. A raw score is converted to a z-score with the following formula: z = (x-m)/sd standardized estimates. Estimates (results) from standardized variables are interpreted the same way for all variables. Mean and sd of variables are determined by the original units of variables. Unstandardized variables are in their original units rather than being expressed as z-scores. Unstandardized variables cannot be directly compared across variables with different scales. A covariance is an example of an unstandardized estimate. It is an unstandardized from of a correlation (rxy) Are the raw units meaningful (ex. survival in years, salary in dollars) This can make interpretation easier and more meaningful. Pearson correlation estimates the degree of linear association between two continuous variables. Its theoretical range is from -1 to 1.