what is a p-value?

Five Thirty Eight has a video of statisticians trying to explain what a p-value is. Well, what’s disturbing to me is that they won’t really try. Then again, the maker of the video very well may have cherry picked the most entertaining answers. I can’t reproduce the research so I have no way of knowing.

Here’s another article slamming the humble p-value. It’s true, there will always be some false positives if the data set is large enough. As an engineer, I try to use statistics to back up (or not) a tentative conclusion I have reached based on my understanding of a system. I will question a statistically significant result using my understanding of a system. That way both statistics and system thinking can reinforce and make each other stronger, rather than our relying exclusively on one or the other. Another way to think about this is that as data sets grow and our traditional engineering system analysis methods are just taking too long to apply, we can use statistics to weed out a lot of the data that is clearly just noise, and then focus our brains on a reduced data set that we are pretty sure contains the signal, although we know there are some false positives in there. So i say relax, use statistics, but don’t expect statistics to be a substitute for thinking. Thinking still works.

 

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