Model+Adequacy+and+Validation

(Regression) Model Adeqacy and Validation (Mulitvariate Methods) (Regression Analysis) (GWU EMSE-271)
Index | Topics (Logical Lectures) | Lectures | Problems | Readings | Nomenclature | Concepts

[Dependent Variable Normality - Probability Plot - AD Statistic | Correlation | Residuals Analysis | Model Significance - F-test | Parsimonicous Model | Coefficient Significance - t-Test | Collinearity - VIF | Heteroscedasticity - Analysis of Residuals | Auto-correlation - DW Statistic | Influential Observations (Outliers | Std. Residuals | DFBETAs | DFITs) | Comparing Models ]

"**Model validation** is possibly the most important step in the model building sequence. It is also one of the most overlooked." - [|Wikipedia]

Van Dorp in EMSE 271 brings up Model Adequacy and Validation, not consistently based on how I did my notes. After thinkig about it for a year.I'm ready to suggest that these seeminly switched and perhaps overloaded terms should be looked at as follow:
 * Model Adequacy includes good enough results and statistical validation.
 * Model Validation (overloaded term) is about checking out alternate variables or data. - pws 1/27/2011


 * Model Adequacy **
 * Goodness-of-Fit (Model - Coefficient of Determination (//R-squared, Adjusted R-squared))//
 * //Correlation (PCA)//
 * Significance
 * Model (F-Test)
 * Individual Parameters (t-test)
 * Statistical Model Validation **
 * Validating that the assumptions made in order to do the particular model hold true
 * Residual Analysis
 * Detecting Problems
 * Multicollinearity ( Variance Inflation Factor | Condition Index (TBD} )
 * Heteroscedasticity
 * Autocorrelation
 * Influential Observations
 * Outliers - Studentized Residuals
 * DFBETAs (See Lattin, pages 63-64)
 * DFITs (Minitab feature)


 * Model Validation **
 * Comparing Models (which combination variable gives the best fit - regression)
 * "Model Validation" ( a la Lattin)
 * Overfitting
 * Cross-Validation
 * Jackknife


 * Sources:**
 * Statistical model validation. (2009, April 14). In //Wikipedia, The Free Encyclopedia//. Retrieved 15:27, December 8, 2009, from []
 * Analyzing Multivariate Data, by James Lattin, Douglas Carroll and Green ([|Amazon]), pp 50-75
 * EMSE 271, Fall 2009

Contributors: Sisson, Schraeder