# Why Does ProbabilityScalePlot Display Censored Observations?

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 I am attempting to reproduce a Weibull probability plot from Wayne Nelson's Applied Life Data Analysis text (pp. 147-9). I enter failure data for 16 field windings thus: windingdata = {31.7, 39.2, 57.5, 65, 65.8, 70, 75, 75, 87.5, 88.3, 94.2, 101.7, 105.8, 109.2, 110, 130}; Seven of the observations are failures and nine are censored observations. In the list below each failure is denoted with a 0 and each right-censored observation is denoted with a 1: censorlist = {0, 0, 0, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1}; I use EventData to assemble these observations: evdata = EventData[windingdata, censorlist] I generate the probability plot thus: ProbabilityScalePlot[evdata, "Weibull", Method -> {"ReferenceLineMethod" -> "Fit"}] The resulting plot includes points for the censored observations, in addition to points for the failures; this is not correct. While the censored observations are not plotted, they cannot simply be deleted --- they are needed in order to determine the plotting positions for the failure points. The reference info for ProbabilityScalePlot indicates that it accepts EventData.Any help would be appreciated.Michael Cushing