Think Like a Statistician – Without the Math
flowingdata.com
flowingdata.com
Two much better articles:
* https://source.opennews.org/en-US/learning/distrust-your-dat...
http://smile.amazon.com/How-Measure-Anything-Intangibles-Bus...
- Have I unwittingly introduced a bias? Is there a selection taking place that I didn't think about when collecting the data? (Eg calling people on landlines to get polling data.)
- Is there a reason why I should expect the dynamics in the dataset occur in the future, or a reason to expect it to be gone? (Eg does the financial market work like it did before the year 2000?)
- If such-and-such hypothesis is true, what else should I be able to find in the data? (Eg suppose crime is caused by non-aborted kids, what other effects should there be? More truancy in schools?)
Examples include, but are not limited to: ignoring prior probabilities (e.g. misuse of p-values), Simpson's paradox, the Monty Hall problem.
I couldn't say it better myself. I admit to loathing when people think that they can finally prove whatever thing they've been long advocating for, now that they have the data that proves it. Besides the huge issue of thinking that data -- by nature of being data, or something -- inherently contains more truth than just someone literally rambling into a spreadsheet...if the dataset is indeed worthwhile, and by that, I mean deep...then whatever foundational beliefs you think were true needs to be re-evaluated in light of examining the data before moving on to prove something.
This is something that I'm reminded of when sampling the public Twitter stream...I use Twitter probably more than I do email, but my perception of what the Twitter community is like -- I.e. Who and from where people participate, the kind of things they tweet about, etc -- are inextricably narrowed by how I've self-selected users to follow. So when just looking at a random sample of everything that is currently being tweeted, it practically feels like I've stepped onto an alternate reality.
Yes there is a point where you get so much into the principles that you don't need to calculate everything anymore. However, that point is not after graduation, but after doing more math than the people around you for about 3-5 years, maybe 10 for some. And a huge part of your intuition would probably be around not needing a calculator to put the numbers together, and about finding many different solutions to the same problem, understanding that each has their pros and cons (e.g., different fittings that all tell you something about your data cloud).
If you answer a broad question with "it depends", it's a good sign you only think you are well trained (happens to all of us all the time). If you think "it depends, if A then B but Z, if C then D but Y, if E then G but X, ..." then you are probably well trained.