Quality Analysis and Outliers: This Time Samoa has Really Crossed the Line

Minitab Blog Editor 05 January, 2012

I am an outlier. Of the people who work in my department, I go to the fewest meetings, I talk with others the least, and I make the least use of our exercise facilities. But this is not because I am negligent, anti-social, or lazy. It is because I am separated from the rest of my department by about 10,000 miles.

You see, my family and I have had the opportunity recently to move to beautiful Sydney, Australia. And at 3 PM on Friday in Pennsylvania, while my colleagues are discussing nonparametric statistics, SIPOC, and project charters, I'm plotting my route to the beach because it is 7 AM Saturday here. It’s all due to the international date line, the imaginary line zig-zagging through the middle of the Pacific, where Tuesday becomes Wednesday, Wednesday becomes Thursday, and Thursday becomes Friday.

Unless you are in Samoa.

Palm tree on a white sandy beachSamoa was also feeling like a bit of an outlier. And for similar reasons. They are located east of the international date line, which put them in good company, including the company of American Samoa, Hawaii, and California. However, Somoa’s most important trading partners, friends, and relatives are in Australia and New Zealand on the other side of the line. So Samoa found itself the odd country out because it was always a day behind.

In quality analysis data, an outlier can be caused by problems with your equipment, operator error, or random accidents. But it is also possible for values to be outliers not because they are defective in some way, but rather because they come from a different population than the rest of the data. Maybe a part was accidently sampled from the wrong production line. Or maybe call center data is from the day after a long weekend, so it is from Tuesday but has more in common with a typical Monday.

Such was the case with Samoa. Samoa was a perfectly good country, but it has more in common with the countries on the west side of the date line than those on the east, so it ended up as a bit of an outlier.

So Samoa took action, and this past week they skipped a day all together, and in so doing managed to move their country across the data line. When the stroke of midnight arrived in the waning hours of Thursday, December 29, Samoans greeted not Friday, December 30, but instead Saturday, December 31. Now Samoans TGIF and hate Mondays on the same day as their friends, family, and business associates in Australia and New Zealand. They have rejoined their natural population and are no longer outliers.

As for me, and my family, we are enjoying our outlier status for now. It's fun relearning how to speak English, count money, and get around. Our friends, family, and colleagues back home are asleep when we are awake; they are worried about frostbite while we're slathering on sunscreen; they are counting their savings while we are slowly going broke. But for that last part, I don’t mind being an outlier for a little while.