An R2 near 1 indicates that a regression line fits the data well, while an R2 close to 0 indicates a regression line does not fit the data very well.

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Or adultesence might be just the opposite: not evidence of progress but another sign of a generalized regression.

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Important cases where the computational definition of R2 can yield negative values, depending on the definition used, arise where the predictions which are being compared to the corresponding outcomes have not been derived from a model-fitting procedure using those data, and where linear regression is conducted without including an intercept.

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Almost a decade ago a study demonstrating regression of atherosclerosis with apo A-1 Milano caused tremendous excitement, but the recombinant product has not yet undergone further research or commercial development.

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