Weibull Analysis: Results (Raw Data)
Weibull and Reliability/Failure Time Analysis
Select variables via the Weibull & Reliability/Failure Time Analysis dialog box
tab and click the OK button in the Weibull & Reliability/Failure Time Analysis dialog box to display the Weibull Analysis: Results (Raw Data) dialog box, which contains three tabs: Quick, Advanced, and Reliability & distribution function.Summary box
The Summary box at the top of the dialog box displays a summary of the parameters established so far in the analysis.
Copy button. Click the Copy button to copy either the selected text (if text has been selected) in the Summary box or all of the text (if no text has been selected) to the Clipboard. Note that the copied text retains formatting information (such as font, color, etc.).


Summary
Click the
Summary button to display a spreadsheet with the current parameter values. If the current parameter values are the maximum likelihood estimates (the default values were not changed in the Shape parameter or
Scale parameter boxes via the
Quick
tab or the Advanced tab), then the spreadsheet will also contain the standard errors and confidence intervals for the parameter estimates. Note that the confidence intervals are based on the information matrix from the maximum likelihood estimation procedure, and they are only approximations (based on the normal distribution). In addition, in the case of the shape and scale parameters, they are adjusted to reflect the fact that the valid parameter space is bounded (i.e., shape and scale must be greater than 0). See Nelson (1990; Section 5.7) or Dodson (1994) for computational details. Also, Dodson (1994) cautions against the interpretation of confidence intervals computed from maximum likelihood estimates when the shape parameter is less than 2; in that case the variance estimates computed for maximum likelihood estimates lack accuracy.If the values were changed in the Shape parameter or Scale parameter boxes via the
tab or the Advanced tab, then the spreadsheet will contain only the current parameter values.Cancel
Click the
Cancel button to close the dialog without performing an analysis and return to the
Weibull & Reliability/Failure Time Analysis dialog box.
Options
Click the
Options button to display the Options menu.
By Group
Click the
By Group button to display the By Group specification dialog box.
Subtopics