Pearson's r is a statistical measure that evaluates the strength and direction of the linear relationship between two continuous variables. It ranges from -1 to 1, where a value of 1 indicates a perfect positive correlation, -1 indicates a perfect negative correlation, and 0 signifies no correlation. This coefficient helps researchers understand how closely related two variables are, such as height and weight. To calculate Pearson's r, data points are plotted on a scatterplot, and the correlation is determined by analyzing how closely the points cluster around a straight line. A higher absolute value of Pearson's r suggests a stronger relationship, while values closer to zero indicate a weaker relationship.