Exercise 13: Understanding Pearson
Product-Moment Correlation Coefficient
1. What is the value of the Pearson r for the relationship between variables 1 and 6? Identify
the variables correlated in this relationship.
-r=0.25**. The variables are perceived quality of care and physician collegiality
2. Describe the correlation r= -0.42** using words. Is this a significant correlation? Provide
rationale.
-r=-0.42 is a negative relationship, where an increase in perceived quality of care is
associated with or related to a decrease in the patient care demand. This is a moderate
relationship since the r value lies between -0.30 and -0.50. It is a significant correlation as
indicated by ** described in the footnote of Table 2 as p<0.01. Since p<0.01 is smaller than
alpha=0.05 for the study, the relationship is statistically signigicant.
3. What percentage of variance is explained by the relationship between the variables
perceived quality of care and patient care demands? Show calcs and round answer to two
decimal places.
-Ans: 17.64% variance explained by the relationship between perceived quality of care and
patient care demands
-r^2 x 100%=% variance explained by a relationship; Calc:
(0.42)^2x100%=0.1764x100%=17.64%
4. Is this relationship between the variables perceived quality of care and patient care
demands clinically important? Provide rationale.
Product-Moment Correlation Coefficient
1. What is the value of the Pearson r for the relationship between variables 1 and 6? Identify
the variables correlated in this relationship.
-r=0.25**. The variables are perceived quality of care and physician collegiality
2. Describe the correlation r= -0.42** using words. Is this a significant correlation? Provide
rationale.
-r=-0.42 is a negative relationship, where an increase in perceived quality of care is
associated with or related to a decrease in the patient care demand. This is a moderate
relationship since the r value lies between -0.30 and -0.50. It is a significant correlation as
indicated by ** described in the footnote of Table 2 as p<0.01. Since p<0.01 is smaller than
alpha=0.05 for the study, the relationship is statistically signigicant.
3. What percentage of variance is explained by the relationship between the variables
perceived quality of care and patient care demands? Show calcs and round answer to two
decimal places.
-Ans: 17.64% variance explained by the relationship between perceived quality of care and
patient care demands
-r^2 x 100%=% variance explained by a relationship; Calc:
(0.42)^2x100%=0.1764x100%=17.64%
4. Is this relationship between the variables perceived quality of care and patient care
demands clinically important? Provide rationale.
