To calculate prediction accuracy between observed and predicted values, a common statistical test is the coefficient of determination, or R-squared, which indicates the percentage of variance explained by the model. The discussion highlights the need to understand the underlying distribution of the data, suggesting that if the data follows a normal distribution, one should estimate the mean and variance using unbiased estimators. The importance of comparing the predicted values to the actual observed values is emphasized to determine the accuracy of the prediction model. The conversation seeks clarity on the specific method used to quantify how well the predictions explain variations in the observed data. Understanding these statistical methods is crucial for evaluating the effectiveness of predictive equations.