You spend a lot of time, talking about variability. Or maybe not a lot of time, but you start out with that because that really is whether numbers work or not.- jd
Related Podcast and Transcription: Interpreting Data
Kaiser Fung: Yes. I think somewhere in the book I have said that you could, in fact, define the field of statistics as the study of variability because what happens is that if there’s no variability, if everything is just like the average, there really is nothing to study because every data set would literally have the same number. The whole field of statistics is there because things don’t happen the same way. It is hard for people to accept. I oftentimes think we like certainty and it’s very difficult to accept, for instance, say in business you like your metrics to be stable, but then it gets difficult to accept the fact that if the whole company pursues the exact same strategy and you don’t change a thing from one month to the next month, the metrics are not going to look exactly the same. There’s some natural fluctuation based on things that you can’t control.
So oftentimes, in my work, you have to convince people that if you’re going to do something different that something different has to be much better than what normally might happen. How do you determine if the difference that you are observing after you changed your ways? Is that real difference or is that just a difference that might happen regardless of anything different that you are doing. So with certainty we are trying to get people to accept the fact that there is some background variability no matter what, it is a big challenge.
About: Kaiser Fung is a statistician with more than a decade of experience in applying statistical methods to unlocking the relationship between advertising and customer behaviors. His blog, “Junk Charts,” pioneered the genre of critically examining data and graphics in the mass media.
Lean Marketing eBooks (More Info): Excerpt from the Lean Marketing House