e/Regression model validation

Information
has gloss	eng: In statistics, model validation is possibly the most important step in the model building sequence. It is also one of the most overlooked. Often the validation of a model seems to consist of nothing more than quoting the R2 statistic from the fit (which measures the fraction of the total variability in the response that is accounted for by the model).
lexicalization	eng: Regression model validation
instance of	e/Statistical model