Beta Eta Gamma Rho

[Tim Smith]

[Originally Posted: 4/14/00-- Transferred by ReliaSoft Moderator]

Could anyone tell me what these mean? Which one is the slope?

[Jim Jauw]

[Originally Posted: 5/16/00-- Transferred by ReliaSoft Moderator]

Tim, Please refer to page 29 of ReliaSoft's Life Data Analysis Reference, the companion reference book that comes with Weibull++5. As the Tech Support reply states, these parameter labels are arbitrary, as other statisticians have labeled Beta and Eta as Alpha and Beta, respectively. Your search for a slope points to linear regression techniques that may not apply to Weibull analysis. Once a Weibull plot is made and an arbitrarily best-fit line is drawn (using MLE, RRX or RRY), you can mathematically compute a slope for comparisons, but the calculator will give you a point estimate for any time chosen without any additional computations (i.e. why would you want a slope?).

[ReliaSoft Tech. Support]

[Originally Posted: 4/26/00-- Transferred by ReliaSoft Moderator]

Beta is the shape parameter or slope. Eta is the scale parameter. Gamma is the location parameter. Rho is the correlation coefficient, which measures how well the data points fit the regressed model. All of the symbols for these parameters can be changes in the File/User Setup/Calculations feature.

[S. Nath]

[Originally Posted: 4/17/00-- Transferred by ReliaSoft Moderator]

Beta