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Struggle With Statistics? Your 'Fixed Mindset' Might Be To Blame (arstechnica.com)

A new study in Frontiers in Psychology examined why people struggle so much to solve statistical problems, particularly why we show a marked preference for complicated solutions over simpler, more intuitive ones. Chalk it up to our resistance to change. From a report: The study concluded that fixed mindsets are to blame: we tend to stick with the familiar methods we learned in school, blinding us to the existence of a simpler solution. Roughly 96 percent of the general population struggles with solving problems relating to statistics and probability. Yet being a well-informed citizen in the 21st century requires us to be able to engage competently with these kinds of tasks, even if we don't encounter them in a professional setting. "As soon as you pick up a newspaper, you're confronted with so many numbers and statistics that you need to interpret correctly," says co-author Patrick Weber, a graduate student in math education at the University of Regensburg in Germany. Most of us fall far short of the mark.

Part of the problem is the counterintuitive way in which such problems are typically presented. Meadows presented his evidence in the so-called "natural frequency format" (for example, 1 in 10 people), rather than in terms of a percentage (10 percent of the population). That was a smart decision, since 1-in-10 a more intuitive, jury-friendly approach. Recent studies have shown that performance rates on many statistical tasks increased from four percent to 24 percent when the problems were presented using the natural frequency format.

22 of 151 comments (clear)

  1. Huh? by dtmos · · Score: 4, Insightful

    Part of the problem is the counterintuitive way in which such problems are typically presented. Meadows presented his evidence in the so-called "natural frequency format" (for example, 1 in 10 people), rather than in terms of a percentage (10 percent of the population). That was a smart decision, since 1-in-10 a more intuitive, jury-friendly approach. Recent studies have shown that performance rates on many statistical tasks increased from four percent to 24 percent when the problems were presented using the natural frequency format.

    I've heard this argument before, and I just don't get it. "Percent" means per hundred, as the word is derived from the Latin "per centum," literally, "per hundred." It's a natural frequency format, just as much as saying "1 in 10 people." It's saying "10 per 100" people. What's so confusing?!?

    1. Re:Huh? by umafuckit · · Score: 4, Insightful

      I've heard this argument before, and I just don't get it. "Percent" means per hundred, as the word is derived from the Latin "per centum," literally, "per hundred." It's a natural frequency format, just as much as saying "1 in 10 people." It's saying "10 per 100" people. What's so confusing?!?

      It's not confusing, it's just that many people don't do the conversion in their heads. Further, presenting the natural frequency is more useful for small percentages: e.g. 1 in 4,000 is definitely easier to digest than 0.025%

    2. Re:Huh? by hey! · · Score: 5, Insightful

      Nobody is saying that 1-in-10 is mathematically different than 10%. It is heuristically more helpful to people with less mathematical competence.

      When you're good at math, you naturally line up all the "givens" in a problem. You go over each one an interpret what it means, "So that means if I had 100 people, ten of them would prefer vanilla to chocolate..." It's like a wood carver examining a block of wood to find a good place to start cutting. You do this so automatically it seems intuitive to you, but it's actually the result of long training and practice.

      To people who aren't as well trained in math, the "givens" look like an impenetrable wall of text, because the individual bricks in the wall don't instantly convey useful information to them. Well, of course they don't; you have to *think* about them, and the less accustomed you are to numbers, the more work it is for you for less certainty of reward.

      But if you put a picture into peoples' heads, you give them an immediate handhold on the problem. It's not difficult for a mathematically fluent person to make his own handhold, but it is a stumbling block for a lot of people.

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    3. Re:Huh? by Anonymous Coward · · Score: 3, Insightful

      "Percent" means per hundred

      A lot of people don't even get that. The problem is innumeracy compounded by poor vocabulary.

    4. Re:Huh? by gweihir · · Score: 2

      2. What makes "1 in 4,000" easier to digest than "0.025%"?

      Probably people being under the illusion they have an accurate image how many 4000 people are (for example). They do not.

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    5. Re:Huh? by hey! · · Score: 2

      So you're saying that the point is, if one replaces the term "10 percent" with "10 per hundred," people would understand the question better?

      Yes. I know it sounds weird, but it's really what you automatically do without planning when you approach a problem. But even if you're pretty good at math, having the problem stated in a slightly different way can help you when you're tackling problems that are hard for you. It's what a professor automatically does when a lot of students get stuck on a problem set question: he restates the problem in a way that enables the students to relate it to things they've already learned.

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    6. Re:Huh? by Calydor · · Score: 2, Insightful

      You seem to be having trouble understanding that different people think in different ways.

      Would it help with a preamble saying that other people are different from you?

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    7. Re:Huh? by hey! · · Score: 2

      Well, that's just another kind of "literacy" too. Everyone I think struggles with the fact that other people are different than they are; but I think quite a few people don't have any idea how different other people can be in their education and abilities.

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    8. Re:Huh? by Anonymous Coward · · Score: 3, Insightful

      Because most people, especially now, have little physical grasp of numbers, beyond what they can count on their hands. Expressing numbers in ratios, rather than percentages, becomes much more meaningful when the percentage gets smaller and the numbers become indivisible by 2. 1 in 700 is much easier to grasp than 0.142%. To paraphrase George Carlin," think of how dumb the average person is, and remember that half of them are dumber than that."

    9. Re:Huh? by clovis · · Score: 3, Insightful

      It's not confusing, it's just that many people don't do the conversion in their heads. Further, presenting the natural frequency is more useful for small percentages: e.g. 1 in 4,000 is definitely easier to digest than 0.025%

      1. What "conversion"?

      2. What makes "1 in 4,000" easier to digest than "0.025%"?

      I suppose it's because .025% is a poor choice of a way to express a value. Percent means parts of a hundred, and they make more sense when the values is between 1 and 100. When you're using percents that are far less than 1%, it is hard to get an intuitive feel for the relative size of whatever is being measured. Sure it's easy enough to do the conversion, but why not express it as a number that is scaled to the measurement in the first place.

      It's sort of like when someone asked for the height of my son. I could say he is 0.0011 mile tall, and although you may have a good feeling for how long a mile is, you have no idea whether he is average, short, or tall until you've done the conversion.

    10. Re:Huh? by Anonymous Coward · · Score: 2, Insightful

      That's a huge problem. Some people never actually grok'ed percent, or division, or power, or exp, or e, or phi, or differential equations, or derivates of such.. Someone could actually be a good mathematician, but still have holes in their elementary understanding. Someone could be an excellent people person and make better estimates, but nobody ever knew why everything they touched turned to gold.

      When you measure everything, you lose the value of everything.

      Captcha: circus

    11. Re:Huh? by Ol+Olsoc · · Score: 2

      Any normally intelligent human being should be able to do math at a level which is quite rare in our society. The problem is that our educational system only produces mathematically literate adults as statistical outliers.

      I think that it is just taught incorrectly. Back in Junior High, I seriously sucked at maths. Algebra was a struggle.

      Then in High school, I had a teacher who insisted on us picking up and learning slide rules, even though they were rapidly becoming obsolete. The moment I finished my first lesson, it was like several locks in my mind opened - almost mentally painful. What was once a pain in the ass was now painfully but joyously obvious.

      I don't know if it was just a fluke for how my particular brain operates, but the "mathemechanical" layout of a slide rule just changed everything. Now I can perfom a lot of stuff in my head with a sort of mental slide rule.

      And when I see the outlandishly idiotic common core math, which would appear to be custom designed to make the subject as difficult as possible, I have to chuckle. Try giving the tykes a slide rule.

      --
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    12. Re:Huh? by preflex · · Score: 2

      Yeah, so?

      Mean, median, and mode are all types of averages.

      Perhaps the "even dumber than that" segment of the population includes you.

    13. Re:Huh? by tlhIngan · · Score: 2

      2. What makes "1 in 4,000" easier to digest than "0.025%"?

      0.025% is not a "people friendly" number. It's a tiny fraction that most people will never see in their lives.

      As an example, show me 0.025% of something. Anything. Perhaps 0.025% of a TV. Or a cup of water. Or your phone's storage. It's hard to visualize simply because it seems to imply "a portion of".

      But 1 in 4000 is more "people friendly" because you're not asking a tiny part of something, but now one unit in a bunch of units. You don't show me 0.025% of a cup of water, but 1 cup of water in 4000 cups. I can't instinctively grasp 0.025% of a cup of water, but I can see a cup, and think I see 3,999 more.

      Think of it this way - we are taught percentages as fractions of a whole. 50% of a cup of water is half a cup. But 1 in 2 cups is 1 cup full of water and 1 empty cup. When your percentages get smaller, it's harder to visualize the tiny part of the whole, but easier to recognize a whole as part of a bigger group.

      And yes, "people friendly" units are very useful. It's why you see storage often measured in CDs and DVDs. And it's easy to confuse - even in the metric system. Take mass for example, it's measured in grams, But you can grasp 1,000 kilograms more readily than if it was stated as 1 Megagram, despite both being the same mass. "Kilogram" is a people unit - everyone's handled kilogram massed things in their lives.

    14. Re:Huh? by houghi · · Score: 2, Insightful

      If you tell me somebody is 0.0011 km tall, the conversion is done pretty quick. You just move it 3 decimals and you have meters. The conversion is not instantly, but not a real issue either.

      A better comparison would be 100 000 seconds is how long? Is that hours, or days?

      --
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    15. Re:Huh? by GLMDesigns · · Score: 2

      Well. We all know that there are 86,400 seconds in a day. So it's roughly 1 1/7 days.

      Duh

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    16. Re:Huh? by gotan · · Score: 4, Informative

      That's not it.

      It's easier to grasp what to do to those numbers. Presented with percentages it's often hard to see what mathematical operations are necessary to arrive at the desired answer in bayesian statistics problems.

      E.g.
      A medicinal test for disease X gives false positives in 0.1% of cases. It gives a false negative in 1% of the cases (i.e. correct positive in 99% of the cases). The disease afflicts 0.01%.
      Of those tested positive, how many have disease X.

      Of course one now could employ the statistics toolbox to solve that problem. OTOH one could compare the 10 in 10,000 false positives (with a slight error since only 9,999 are without disease), to the 1 in 10,000 diseased (noticing that the false negatives have negligible impact for the question at hand and we can work with 100% correct positives as well as 99% if we want an estimate).

      So now we need to compare only small numbers, 10 false positives to 1 diseased positive or 1 in 11 which is about 9%.
      (the correct result without the approximations is 10 in 111 or 9,009...%).

      Also note the easy expansion of 1 in 1,000 to 10 in 10,000 to get to comparable numbers. It's not important to have an accurate image of those 10,000, what's of interest is to compare the 10 false positives to the 1 diseased.

      Such medicinal tests help a lot to find candidates that should undergo more sophisticated (and much more expensive) tests, to see if they really have X (it'll reduce the expensive tests by a factor of 1,000), but patients need to be informed even with a "positive" result it's still unlikely that they have X, but advisable to do the more sophisticated test. One might think that the test is pretty useless if it delivers 91% false positives when in fact it is pretty accurate, only the occurence of disease X is so rare.

      So such "frequencies" do not only help to get a (pretty) correct result without knowing any bayesian statistics tools, but also to understand how the information affects the result, and how the unintuitive (to someone not used to such statistics) result comes about.

      --
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  2. Radical shift in curriculum by ahoffer0 · · Score: 2

    I've thought long and hard about this problem. After wrestling with it for a few years I'm ready to support a radical shift in public education.

    Use the term "math" (or "maths", depending on your version of English) to refer to arithmatic, geometry, and algebra
    "quantithinking classes".

    Dump trigonometry and calculus from the curriculum. Replace with statistics, probability, design of experiments, and critical thinking. Call this new subject "quantitative thinking" (or whatever name you want) and give it equal billing as as language, math, science, literature, and physical education.

  3. Intuitive And Jury Friendly by tsqr · · Score: 5, Funny

    Recent studies have shown that performance rates on many statistical tasks increased from four percent to 24 percent when the problems were presented using the natural frequency format.

    Hmm, let me make that more intuitive and jury friendly for everyone: recent studies have shown that performance rates on many statistical tasks increased from 1 in 25 to about 1 in 4 when the problems were presented using the natural frequency format.

  4. Even more jury-friendly ... by fahrbot-bot · · Score: 3, Funny

    ... since 1-in-10 a more intuitive, jury-friendly approach.

    Which would be 1-in-12.

    --
    It must have been something you assimilated. . . .
  5. Bound for failure by reanjr · · Score: 4, Insightful

    If you can't figure out 10% is 1-in-10, you have no hope of wading through the standard level of obfuscation added to any publication when discussing statistics.

  6. Statistics by ledow · · Score: 5, Interesting

    I'm a mathematician.

    The second someone digs out statistics, I can always pick 20 holes with their methodology used, presentation of, choice of, or analysis of their numbers. Usually, I could make things come out "oppositely" with only minor tweaking and use of the other statistics from the same dataset that they discarded out of hand, and usually I could provide much better justification for the numbers I used than the ones they did.

    People use statistics to back up their claims. That's it. And if you go looking hard enough and present statistics to do that, you can ignore all the stuff that doesn't match your claims. It's really easy to do.

    And because nobody understand statistics (I would posit this category even includes statisticians!), you can get away with it.

    I like to shout at shampoo adverts when they say "Women agree*" where the * leads you to a footnote saying they tested 19 women and 67% of those agreed... so you're telling me that, actually, worldwide, 12.7 women agreed... What the hell kind of selection criteria did you use to get that, and what use is that if you don't specify that they were random women from the street in a controlled trial rather than, say, the people who work in the office?

    The old saying is right - there are lies, damn lies and statistics. If someone quotes statistics are you, assume it's a lie. It almost always is. Even when it's not, it's merely the portion of the truth that can be spun positively if you don't mind looking through an n-dimensional kaleidoscope at the data.

    And what are they trying to do by telling you this? They're trying to tell you "Hey, look, you're stupid and have no idea what's going on and actually everyone else is really onboard". Statistics are used as the worst kind of "peer pressure" - if they are trying to convince you of something, rather than inform you.

    Statistics can be incredibly useful, very revealing, and can lead to a better understanding. If you get them from a professional. Who'll then tell you what the statistics *mean* and whether or not they have caveats.

    If you get them from shampoo ads and random junk on the Internet, they are no better than any other "fact" spewed at you in such a manner... wrong.

    (Interesting fact: There's a TV program called QI, in which all kinds of "you'll never believe" stuff is presented in what's supposed to be a highly intellectual quiz show. QI facts are heavily researched, almost always counter-intuitive or contrary to what everyone has been told, and they spend years with some of the cleverest people from the top universities doing research for each series. And in one episode they reveal that the portion of facts that they themselves got wrong, or which have changed since, was over 50%).

    If someone quotes statistics at you, don't just nod and go "Oh really?" because you're then likely to repeat that statistic without every checking it. The correct response is to think "What's he trying to convince me of?". Because you don't use statistics for anything else.

    And unless you understand, truly understand, statistics, you know that any kind of amateur data-gathering or analysis by even the most well-intentioned people is a bottomless pit of potential failure.

    Hell, to be honest, 99% of the time, I can't even work out the right answer for some statistics so I make it up and say 99%.