Regression Tests and Models

A verified 649-case guide to constructed survival time, partial likelihood, hazard ratios, proportional-hazards diagnostics, and separate Python, R, SPSS, and Excel results.

A verified random-intercept analysis of 649 students in two schools, with centered Python ML, R REML, a transparent SPSS failure audit, exact diagnostics, and code.

A verified 649-row Poisson count model with exact log-link formulas, rate ratios, underdispersion diagnostics, software workflows, charts, and downloads.

A verified 649-row quantile regression at 0.25, 0.50 and 0.75 with exact check-loss formulas, coefficient comparisons, diagnostics, and software resources.

A verified quasi-Poisson guide showing how Pearson scale 0.2431 changes standard errors while preserving log-link estimates and rate ratios.

A verified 649-student guide to random-intercept modeling, fixed effects, variance components, ICC, clustered prediction and Python, R, SPSS and Excel diagnostics.

A verified 649-case R Squared guide covering sums of squares, adjusted fit, nested changes, predictor comparisons, diagnostics, and matched Python, R, and SPSS evidence.

Binary probabilities estimated with the standard normal cumulative distribution Probit Regression: Formula, Interpretation, Python, R, SPSS and Excel Guide Probit Regression models a binary outcome by…

PCA dimension reduction, validated component selection and regression Principal Component Regression: Formula, Interpretation, Python, R, SPSS and Excel Guide Principal Component Regression turns correlated predictors into…

Curved relationships estimated with linear-model machinery Polynomial Regression: Formula, Interpretation, Python, R, SPSS and Excel Guide Polynomial Regression extends a linear model by adding squared, cubic,…