Quality Digest’s picture

By Quality Digest

Giving Thanks

I have been a faithful and interested reader of Quality Digest and the “Quality Curmudgeon” column for many years. As is usually the case, I breeze through the magazine and then cut out the last page so I can take my time with it at a later point in time. I started this back in the day when I realized I cut them out for future reference or to forward to a colleague anyway.

I had not taken the time to read the “Give Thanks” column (December 2008) because, as vice president of sales and marketing for my company, I was too busy working my crazy hours keeping things afloat. Ironically, I have plenty of time to read old items I have saved, such as your column, since today is my first day of unemployment. As the 88-year-old patriarch of the family-owned business told me this past Friday, “Look at this as a learning experience. We can now get three college kids to do the work of a six-figure executive such as yourself.” With that they showed me the door. Ouch!

Donald J. Wheeler’s picture

By Donald J. Wheeler

The number of major hurricanes in the Atlantic since 1940 (as we considered in my February column, “First, Look at the Data”) are shown as a histogram in figure 1, below. Some analysts would begin their treatment of these data by considering whether they might be distributed according to a Poisson distribution.

The 68 data in figure 1 have an average of 2.60. Using this value as the mean value for a Poisson distribution, we can carry out any one of several tests collectively known as “goodness-of-fit” tests. Skipping over the details, the results show that there’s no detectable lack of fit between the data and a Poisson distribution with a mean of 2.60. Based on this, many analysts would proceed to use techniques that are appropriate for collecting Poisson observations. For example, they might transform the data in some manner, or they might compute probability limits to use in analyzing these data. Such actions would be wrong on several levels.