Regression

Regression models relate an outcome variable to one or more predictors, producing a formula you can inspect rather than a black-box prediction. Every model here reports its coefficients, a measure of overall fit, and residual behavior alongside the prediction itself, since a model that fits poorly can still produce a confident-looking number if you only look at the prediction.

These tools calculate sample size, parameter count, and residual patterns directly from your data, but whether your predictor and outcome were measured in a valid temporal order, whether important variables were omitted, and whether prediction beyond your data's range is appropriate are left for you to verify.