INFORMS Open Forum

  • 1.  All models are wrong, some are useful -- an essay

    Posted 02-14-2017 15:15
    Dear INFORMS members:

    I wanted to share to share a recent essay I wrote for a science/humanities website called 3 Quarks Daily (readers of this website are typically not aware of operations research).

    http://www.3quarksdaily.com/3quarksdaily/2017/02/all-models-are-wrong-some-are-useful.html [link]

    The piece tries to distinguish between math models as they apply to physical and social sciences. Most of what I write here obvious to an INFORMS member -- who hasn't heard of George Box's famous quote that all models are wrong -- however my point is that, despite knowing this, we can easily get overconfident with our models (maybe we are drawn to their mathematical elegance when that elegance may not have to do much with reality) and in assuming that we know more than we actually do. This particularly true since most of what we do applies to social systems where the quirks of human behavior are not easily accounted for.

    Comments are welcome!

    Hari Balasubramanian
    people.umass.edu/hbalasub

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    Hari Balasubramanian
    Associate Professor
    Univ of Massachusetts- Amherst
    Amherst MA
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  • 2.  RE: All models are wrong, some are useful -- an essay

    Posted 02-15-2017 10:20
    Nice article Hari. Even reading the "obvious" is nice when it is well written. Served me as a reminder to not take the obvious for granted. Nice quotes from math/econ luminaries, but the best quote was from your Aunt. Perfectly summarized your point. Thanks for sharing.

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    Zahir Balaporia
    Optimization Solutions Partner
    FICO
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  • 3.  RE: All models are wrong, some are useful -- an essay

    Posted 02-15-2017 17:02
    Thank you for the kind words, Zahir!

    Hari Balasubramanian
    people.umass.edu/hbalasub 


  • 4.  RE: All models are wrong, some are useful -- an essay

    Posted 02-15-2017 17:40
    Hari,

    RE: Once in a while we get something remarkably successful like Nate Silver's election forecasts, which aggregate and weight various polls. So successful that we are lulled into thinking that there is a rock-solid science of predicting how a population will vote in an election. This perception lasts until an election like 2016 comes along. Looking at the comments section of Silver's website on Nov 9, 2016 you could feel the anger – and the anger turned on the pollsters and statisticians: how could everyone get it wrong?   

    RESP: There are many pretenders out there.  No one should assume that qualified statisticians were involved with these polls/forecasts.  Better research tends to mention qualifications; it is part of the information.  These polls seldom mention qualifications. 

    We know how to build rock-solid polls when needed.  What we do not know how to do is to convince every decision maker to spend the money to hire it right and do it right.  I doubt if many of these polls would survive any statistical scrutiny; they are not designed for that.  That costs money and economically, these polls are just for propaganda (creating a band-wagon effect) and entertainment.  I have seen obvious manipulation of the results.  Furthermore, you can read about all the statistical mistakes made by nonstatisticians on early polls.  You should blame the decision makers when they do not follow Best Statistical Practice. 

    ASA introduced the PSTAT so that knowledgeable consumers can better discern qualifications.  I wrote three chapters addressing these problems in the field--lots to say. 

    Today, my articles/blogs have titles like, 'The Coming Flood Of Statistical Malfeasance.' 

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    Randy Bartlett
    Big Data Scientist
    Blue Sigma Analytics
    Phoenixville PA
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  • 5.  RE: All models are wrong, some are useful -- an essay

    Posted 02-15-2017 18:56
    Many thanks first of all for reading the essay and for the clarifications. I used a somewhat broad brush approach in the essay. I agree with you on the issues you raise about the polls and the possibility of designing good ones. 

    Some of the things you mention, however, only appear to confirm my point (in other parts of the essay) that decision-making on such matters is far from rational. The presence of pretenders, avoiding the costs of creating good polls, the role of propaganda and the need to create entertainment, manipulation of results -- as you note these seem to stand in between. But will it be possible to ever have an environment where such behavioral aspects can be minimized? If these are minimized, will new and unexpected ones emerge? 

    I don't have any answers here and am not an expert in this domain, but it seems to me that these are precisely the things that makes social systems so challenging. 

    Hari


  • 6.  RE: All models are wrong, some are useful -- an essay

    Posted 02-16-2017 00:32
    RE: But will it be possible to ever have an environment where such behavioral aspects can be minimized?
    RESP: Yes, we have polls that employ Best Statistical Practice.  Step 1: Look for the proper qualifications.  If you buy snake oil from a pharmacist, then it is the pharmacist's fault.  If you buy it on the street, then that is your problem. 

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    Randy Bartlett
    Big Data Scientist
    Blue Sigma Analytics
    Phoenixville PA
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