A tool used primarily in statistical analysis, it computes a modified version of the coefficient of determination (R-squared). This modification accounts for the number of predictors in a regression model, providing a more realistic assessment of the model’s goodness of fit compared to the standard R-squared. For instance, when comparing two models predicting the same outcome variable, the one with a higher modified coefficient might be preferred even if its standard coefficient is slightly lower, especially if the former utilizes fewer predictor variables.
This refined metric addresses a key limitation of R-squared, which tends to increase with the addition of more predictors, regardless of their actual relevance. It offers a valuable approach to model comparison and selection, particularly in situations with multiple potential explanatory variables. By penalizing models with excessive predictors, it encourages parsimony and helps researchers identify models that strike a balance between explanatory power and simplicity. This approach ultimately contributes to building more robust and generalizable statistical models, a crucial goal across scientific disciplines since the development of regression analysis.
