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I Am 95 Percent Confident June 9, 2013

Posted by Peter Varhol in Education, Technology and Culture.
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I spent the first six years of my higher education studying psychology, along with a smattering of biology and chemistry.  While most people don’t think of psychology as a disciplined science, I found an affinity with the scientific method, and with the analysis and interpretation of research data.  I was good enough at it so that I went from there to get a masters degree in applied math.

I didn’t practice statistics much after that, but I’ve always maintained an excellent understanding of just how to interpret statistical techniques and their results.  And we get it wrong all the time.  For example:

  • Correlation does not mean causation, even when variables are intuitively related.  There may be cause and effect, or it could be in reverse (the dependent variable actually causes the corresponding value of the independent variable, rather than visa versa).  Or both variables may be caused by another, unknown and untested variable.  Or the result may simply have occurred through random chance.  Either way, a correlation doesn’t tell me anything about whether or not two (or more) variables are related in a real world sense.
  • Related to that, the coefficient of determination (R-squared) does not “explain” anything in a human sense.  There is no explanation in our thought patterns.  Most statistics books will say that the square of the correlation coefficient explains that amount of variation in the relationship between the variables.  We interpret “explains” in a causative sense.  Wrong.  It’s simply that the movement between two variables is a mathematical relationship with that amount of variation.  When I describe this, I prefer using the term “accounts for”.
  • Last, if I’m 95 percent confident there is a statistically significant difference between two results (a common cutoff for concluding that the difference is a “real” one), our minds tend to interpret that conclusion as “I’m really pretty sure about this.”  Wrong again.  It means that if I conducted the study 100 times, I would draw the same conclusion 95 times.  And that means five times I will draw the opposite conclusion.
  • Okay, one more, related to that last one.  Statistically significant does not mean significant in a practical sense.  I may conduct a drug study that indicates that a particular drug under development significantly improves our ability to recover from a certain type of cancer.  Sounds impressive, doesn’t it?  But the sample size and definition of recovery could be such that that the drug may only really save a couple of lives a year.  Does it make sense to spend billions to continue development of the drug, especially if it might have undesirable side effects?  Maybe not.

I could go on.  Scientific experiments in the natural and social sciences are valuable, and they often incrementally advance the field in which they are conducted, even if they are set up, conducted, or interpreted incorrectly.  That’s a good thing.

But even when scientists get the explanation of the results right, it is often presented to us incorrectly, or our minds draw an incorrect conclusion.  A part of that is that a looser interpretation is often more newsworthy.  Another part is that our minds often want to relate new information to our own circumstances.  And we often don’t understand statistics well enough to draw informed conclusions.

Let us remember that Mark Twain described three types of mendacity – lies, damned lies, and statistics.  Make no mistake, that last one is the most insidious.  And we fall for it all the time.

Of Software, Marketing, and Diversity June 7, 2013

Posted by Peter Varhol in Technology and Culture.
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Oh, Shanley.  It pained me to read your latest missive on the marketing chick and the culture of misogyny.  It pained me because you are sometimes right, but perhaps more often not (or, to be fair, visa versa).  Yes, I’ve seen what you describe, although I would suspect not with the raw intensity you have.

Part of that raw intensity, I suspect, is driven by the Silicon Valley culture.  Whatever exists in America is magnified by the hype that the Valley types like to bring to anything that exists within its confines.

Many of us are too full of ourselves to recognize the value of others in a common endeavor.  Because we are not confident of our own position, we naturally if unreasonably order ourselves at the top of an uncertain food chain.  That means we tend to denigrate those without our particular skill set.

But that particular culture is nowhere near universal.  Many (I have no idea what percentage, but I suspect most) grow out of it.  Those who don’t are sentenced to a life of bad pizza, online games, and no social life.  They pay for their inability to adapt.

There is no single techie who can build, market, sell, and service a software product, and that hasn’t been possible for at least 30 years, if ever.  We all know that the most elegant and advanced technical solution is not likely to win in the market.  Those that build those technical solutions are at a loss to understand why they aren’t accepted, and are more likely to blame others than themselves.

So we create the marketing chick and denigrate her, even though marketing is a necessary skill for success.

It is a human failing, with the intensity increased by the win at all costs mentality in Silicon Valley.  Perhaps you see so much of it because of where you are.  That’s not to say it is right.  But it is to say that elsewhere it may be different.

Really Big Data and the Pursuit of Privacy June 7, 2013

Posted by Peter Varhol in Technology and Culture.
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There’s been so much excitement these days about the commercial potential of Big Data that we’ve forgotten that the Federal government is in the best position to obtain and analyze many terabytes of data.  We were reminded of that in a big way following revelations that the National Security Agency (NSA) was obtaining under secret court order information about all phone calls made by Verizon customers.  I am not a Verizon customer, but I have no doubt that the same court orders exist for other carriers.

(Interesting side note:  Many years ago, after I earned my MS in Math, I had a job offer to join the NSA as a civilian cryptologist.  Perhaps now I wish I had taken it.)

With virtually unlimited fast computing power, the NSA can identify patterns that provide a basis for follow-up law enforcement activities.

Here’s a simple example of how it works.  A computer program identifies twenty or so different phone numbers in the New York City area that have called the same number in, oh, the Kingdom of Jordan about two hundred times in the last two months.  The number in Jordan is a suspected front (through other sources) for some sort of terrorist activity.  This connection might provide law enforcement reason to look more closely into the activities of those making these calls.  That’s not inherently a bad thing.

Of course, there are ways that terrorists and criminals can combat this, such as the use of prepaid and disposable cell phones bought with cash, calling cards, and even random pay phones.  At best, analyzing call records represents one tool among many in the pursuit of wrongdoing, and not really a “Big Brother is Watching” scenario.

From a privacy standpoint, I’m mostly sanguine about the NSA collecting and analyzing calling data.  I’m not engaged in terrorist or criminal activities, and my phone calls are just a few data points among the billions out there.  I’m not directly threatened, or even inconvenienced.

But . . . there may be a slippery slope here.  The definition of suspicious calling activity may gradually expand to include things that aren’t illegal, but perhaps just unethical or embarrassing.  Once you have the data and the computing power, you can start looking for other things.  Call it scope creep, an all-too-common affliction of many projects.

And in a larger sense, many of our freedoms are actually constructed on the premise that the Federal government cannot connect the dots between the myriad of records held by the many Federal agencies on each of us.  Call it privacy by disorganization, but it has worked at least throughout my lifetime to protect my liberties.  But thanks to the advancements made in Big Data over the last several years, we may be seeing the end of that type of protection.

Security and privacy represent direct tradeoffs.  Unlike many Americans, I would prefer to be a little less secure and a little more private.  But the majority does rule, and I do believe that the majority has little issue with the current state of affairs.