The coefficient of correlation is a statistical measure that indicates the degree and direction of relationship between two variables. In nursing education and research, it plays a crucial role in analyzing associations between variables such as students’ academic performance and study habits, patient satisfaction and quality of nursing care, stress levels and coping mechanisms among nurses, or the relationship between nurse–patient ratio and patient outcomes. It helps nurse researchers determine whether and how strongly pairs of variables are related. The most commonly used coefficient of correlation is Karl Pearson’s coefficient of correlation, denoted by “r.” It measures the linear relationship between two continuous variables. The value of r ranges from –1 to +1. A value of +1 indicates a perfect positive correlation, meaning that as one variable increases, the other also increases in a perfectly linear manner. A value of –1 indicates a perfect negative correlation, meaning that as one variable increases, the other decreases in a perfectly linear manner. A value of 0 indicates no linear correlation between the variables. In nursing research, a positive correlation may be observed between the level of nursing education and competency in clinical skills. As the level of education increases, competency may also increase, resulting in a positive correlation. Similarly, a negative correlation might be found between nurses’ workload and job satisfaction; as workload increases, job satisfaction may decrease.