You say its cold out today. I
disagree, it is merely brisk. Subjective descriptions can be vastly different because
of the multitude of factors influencing them. However, we can both agree that
the temperature is 18o. Numbers are great in this way, because they
can describe things objectively. But objective descriptions are still manipulatable
by context. As in the previous example, I could also say that it was -8o,
and again that would be absolutely true. The difference is in what units of measure
I am using to describe the temperature. Context is crucial to interpreting a
statement, as what may be true may not also be meaningful in the present
situation.
One of my favorite examples is the following:
I can flip a coin, and have it land heads up ten times in a row. Now, this isn’t
a trick coin or some special flipping technique, anyone could replicate this.
So hopefully at this point your thinking: “Impossible! I learned statistics in
school. I know that the probability of an event is the number of outcomes that
describe that event divided by the total number of possible outcomes.”
You are correct. In this case if you flip
a coin ten times, the number of total events is 1024, of which only one of
those describes a coin landing heads up all ten times. That is a probability of
roughly one tenth of a percent. But I said I could get ten heads in a row. The key
point is in what I did not say. I did not say I would only be flipping the coin
ten times. In fact, I would have to flip the coin 2046 times on average, but
eventually I would come up with ten heads in a row.
Context is everything. Research has come a
long way in improving internal validity, that is how well data describe the
actual effect of an intervention. But reporters often overlook external
validity, that is how well do the data describe subjects other than the
research participants. So, when they say dark chocolate or wine is good for you.
Remember that the “you” they are referring to might not be you. Dark chocolate is
high in antioxidants, but only the really
dark stuff, and even then, the high saturated fat content and added sugars
are certainly not healthy. Likewise, red wine is only comparatively good for
you in the context of alcohol. It definitely has more going for it than beer,
but your still probably better off not drinking any alcohol at all.
News stories are constantly telling us
about some new ground-breaking study. Apparently, marijuana is a cure all for
every disease known to man. Yet doctors don’t seem to be recommending it very
often. Some will tell you it is all part of the big pharma conspiracy. But more
than likely, its because those studies don’t mean anything when you compare them
to the weight of our current medical knowledge. As more data is generated that
may shift, but for now, do you want to try to control your seizures with
marijuana because it worked for this one kid in Canada, or do you maybe want to
try one of these other drugs first; that we have been using for years, that we
know have worked for thousands of people, that have established dosing schedules
to reduce the time to therapeutic concentrations, drugs whose short term and
long term side effects and drug interactions have been extensively studied. If
those don’t seem to work, by all means, try marijuana, but don’t expect it to
be any reputable doctors ‘go to’ anytime soon.
-AMS
