Tham khảo tài liệu 'engineering statistics handbook episode 1 part 8', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | . Probability Plot Correlation Coefficient Plot Definition The PPCC plot is formed by Vertical axis Probability plot correlation coefficient Horizontal axis Value of shape parameter. Questions The PPCC plot answers the following questions 1. What is the best-fit member within a distributional family 2. Does the best-fit member provide a good fit in terms of generating a probability plot with a high correlation coefficient 3. Does this distributional family provide a good fit compared to other distributions 4. How sensitive is the choice of the shape parameter Importance Many statistical analyses are based on distributional assumptions about the population from which the data have been obtained. However distributional families can have radically different shapes depending on the value of the shape parameter. Therefore finding a reasonable choice for the shape parameter is a necessary step in the analysis. In many analyses finding a good distributional model for the data is the primary focus of the analysis. In both of these cases the PPCC plot is a valuable tool. Related Techniques Probability Plot Maximum Likelihood Estimation Least Squares Estimation Method of Moments Estimation Case Study The PPCC plot is demonstrated in the airplane glass failure data case study. Software PPCC plots are currently not available in most common general purpose statistical software programs. However the underlying technique is based on probability plots and correlation coefficients so it should be possible to write macros for PPCC plots in statistical programs that support these capabilities. Dataplot supports PPCC plots. NIST SEMATECH HOME tools AIDS search ÍBACK next http div898 handbook eda section3 4 of 4 5 1 2006 9 56 52 AM . Quantile-Quantile Plot Sample Plot This q-q plot shows that 1. These 2 batches do not appear to have come from populations with a common distribution. 2. The batch 1 values are significantly higher than the .
