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MANE 6313

Week 7, Module G

Student Learning Outcome

  • Select an appropriate experimental design with one or more factors,
  • Select an appropriate model with one or more factors,
  • Evaluate statistical analyses of experimental designs,
  • Assess the model adequacy of any experimental design, and
  • Interpret model results.

Module Learning Outcome

Analyze a Single Replicate of a \(2^k\) with Center Points using R, part 2


Lack of Fit Test

  • Addition of center points also enables a test for lack of fit
  • Null Hypothesis is \(H_0:\mbox{There is no lack of fit in model}\)
  • Alternative Hypothesis is \(H_1:\mbox{ There is lack of fit in model}\)

RSM ANOVA

Lack of Fit


Test for Pure Quadratic Curvature

  • A second-order response model is defined to be
\[ y=\beta_0+\sum_{j=1}^k\beta_jx_j+\sum_{i<j}\sum\beta_{ij}x_ix_j+\sum_{j=1}^k\beta_{jj}x_j^2+\varepsilon \]
  • Notice the model contains interaction terms and pure quadratic terms

  • Tests the hypothesis that \(H_0:\sum_{j=1}^k\beta_{jj}=0\) vs. \(H_1:\sum_{j=1}^k\beta_{jj}\neq 0\)

  • Calculate one degree of freedom sum of squares for pure quadratic curvature

\[ SS_{\mbox{pure quadratic}}=\frac{n_cn_f(\bar{y}_f-\bar{y}_c)^2}{n_f+n_c} \]

Test for Pure Quadratic Curvature, continued

  • Perform \(F\) test
\[ F_0 =\frac{SS_{\mbox{pure quadratic}}}{MS_{\mbox{residuals}}} \]
  • Rejection Region

Reject \(H_0\) if \(F_0>F_{\alpha,1,df_{\mbox{residuals}}}\)


Test for Pure Quadratic Curvature

Curvature Test


Residuals - Normality

Residuals - Normality


Residuals versus Time

Residuals vs. Time


Residuals versus Fitted Values

Residuals vs fitted


Residuals versus Factor A

residuals vs Factor A


Residuals versus Factor B

residuals vs Factor A


Residuals versus Factor C

residuals vs Factor A


Residuals versus Factor D

residuals vs Factor A