Aim: How do we calculate and interpret correlation coefficients with SPSS? SPSS Assignment Due Friday 2/12/10

Correlation Coefficient Correlation Coefficient is a statistic that indicates the strength and direction of the relationship between two variables for one group of participants It provides a single numerical value to represent the relationship Correlation coefficient can range from (perfect, inverse relationship) to 1.00 (perfect, direct relationship), with the value 0.00 indicating no relationship

Correlation Coefficient: Pearson r Pearson r should be used when the following conditions are met: 1.Interested in a relationship between two scale variables 2.The distribution of scores is approximately symmetrical 3.The relationship is not curvilinear

Describing the Strength of Relationships Based on Correlation Coefficient Rough rules of thumbs… 1.A value of 0.00 indicates “no relationship” 2.Values between.01 and.24 may be called “weak” 3.Values between.25 and.49 may be called “moderate” 4.Values between.50 and.74 may be called “moderately strong” 5.Values between.75 and.99 may be called “very strong” 6.Value of 1.00 is called “perfect” What is true for positives is true in the negative too

Reporting Correlation Coefficients in a Research Report Statement hat presents a Pearson r: – “The relationship between Math Scores and English Scores is a direct and weak (Pearson r =.83)” *NOTE: the letter r in Pearson r must be italicized *NOTE: must use two decimals always OR – “The value of the Pearson r is 1.00, which indicates a perfect, direct relationship.” *NOTE: the letter r in Pearson r must be italicized *NOTE: the description of the relationship is italicized *NOTE: must use two decimals always