DOE Analysis¶
Analysis has three stages: fit a model, read the report, then use the model.
Fit a model¶
- Regression, the command you run. It picks the engine from each output's type, so there is nothing to choose.
The three engines, for reference:
| Engine | For | Page |
|---|---|---|
| Ordinary Least Squares | quantitative outputs | Ordinary Least Squares Regression |
| Binary Logistic | two-outcome outputs | Binary Logistic Regression |
| Nominal Logistic | outputs with three or more unordered outcomes | Nominal Logistic Regression |
There is no ordinal engine. See the note on Regression.
Read the report¶
- Regression Results for OLS
- Regression Results for Binary Logistic
- Regression Results for Nominal Logistic
- The DOE Advisor, the block of findings the regression writes below itself, and the runs it marks red on the design sheet
- Uncoded Coefficients, the same fit reported in each factor's own units, for when you want the equation rather than the significance
Use the model¶
- Optimize, search the model for settings that meet a goal
- Charts, ten ways to look at the fit, including the two under the menu's Regression Diagnostics heading
Nothing in the software imposes an order on these. The only prerequisite is a regression sheet, which Optimize and the regression-source charts need and the design-source charts do not. See Chart Source.
The mathematics¶
- Sums of Squares, the ANOVA table and the per-term tests
- Prediction Equation, how a predicted value is formed
- Design Coding, what a coefficient's units are