Tuesday, March 24, 2015

The danger of weak arguments

Weak arguments are not neutral, they are damaging for technical or scientific propositions.

There's overwhelming evidence for the proposition "Earth is much older than 6000 years." (It's about 4.54 billion years old, give or take fifty million.) Let's say that Bob, who likes science, as long has he doesn't have to learn any, is arguing with Alex, an open-minded young-Earth creationist:

Alex: Earth was created precisely on Saturday, October 22, 4004 B.C., at 6:00 PM, Greenwich Mean Time, no daylight savings.

Bob: That's ridiculous, we know from Science(TM) that the Earth is much older than that.

Alex: What science? I'm willing to listen, but not without details.

Bob: Well, scientists know exactly and it was in Popular Science the other day, too.

Alex: What did the Popular Science article say?

Bob: I forget, but it had two pretty diagrams, lots of numbers, and a photo of Neil DeGrasse Tyson in his office. He has a wood model of Saturn that he made when he was a kid.

Alex: So you don't really know how the age of the Earth is calculated by these scientists, you're just repeating the conclusion of an argument that you didn't follow. Maybe you didn't follow because it's a flawed argument.

Bob: I don't remember, it's very technical, but the scientists know and that's all I need. Why don't you believe in Science(TM)?

Alex: It appears to me that your argument is simply intimidation: basically "if you don't agree with me, I'll tag you with a fashionable insult." Perhaps that's also the argument of the scientists. They certainly sound smug on television, as if they're too good to explain themselves to us proles.

Alex, despite his nonsensical belief about the age of the Earth, is actually right about the form of argument; by presenting a weak argument for a truthful proposition, Bob weakens the case for that proposition. Note that this is purely a psychological or Public Relations issue. Logically, a bad argument for a proposition shouldn't change the truth of that proposition. Too bad people's brains aren't logical inference machines.

(There's a Bayesian argument for downgrading a belief in a proposition when the case presented for that proposition is weak, but a rational person trying to learn in a Bayesian manner the truth of a proposition will do a systematic search over the space of arguments, not just process arguments collected by convenience sampling.)

This is one of the major problems with people who like science but don't learn any: because of the way normal people process arguments and evidence, having many Bobs around helps the case of the Alexes.

A weak argument for a true proposition weakens the public's acceptance of that proposition. People who like science without learning any are fountains of weak arguments.

Let's convince people who "like science" that they should really learn some.

Friday, March 20, 2015

Adventures in science-ing among the general public

I've been running an informal experiment in social situations, based on an example by physicist Eric Mazur:

A light car moving fast collides with a slow heavy truck. Which of the following options is true?

a) The force that the car exerts on the truck is smaller than the force that the truck exerts on the car.


b) The force that the car exerts on the truck is equal to the force that the truck exerts on the car.


c) The force that the car exerts on the truck is larger than the force that the truck exerts on the car.


d) To know which force is larger (that of the car on the truck or that of the truck on the car) we need to know more details, for example the speed and weight (mass, really) of each vehicle.


The majority in my convenience sample pick the last option, d. Included in this sample are people with science and engineering degrees. Most of the people I asked this question can quote Newton's third law of motion: when prompted with "every action has..." they complete it with "an equal and opposite reaction."

So far my convenience sample replicates Mazur's results.

But unlike his measurement (which was made with those classroom clickers that universities use to avoid hiring more faculty and having smaller, more personalized class sessions), mine sometimes comes with arguments, explanations, and resistance.

And here's the interesting part: the farther the person's training or occupation is from science and technology, the stronger their objections and attempts to argue for d, even as they quote Newton. I don't think this is the Dunning-Kruger effect. It's more like a disconnect between concept, principle, meaning, and application.

It's not like linking concepts to principles and meaning and then applying those concepts is important, right? Especially in science and engineering...

Sunday, March 15, 2015

Discussing technical material ≠ arguing opinions

A problem of discussing [minimally] technical material with educated non-technical people is that they don't understand the difference between arguing opinions and discussing technical material.

This problem becomes much greater when the material is probability and when the example is something that the non-technical persons have been using for a while to assert their mastery of quantitative thinking.

Take, for example, the boy-girl problem: "one of two children is a boy, how likely is it that the other is also a boy?"

The right answer is one-half, though figuring that out requires some minimal understanding of probability, namely the difference between states and events and the mechanics of using prior and conditional probability to compute a posterior probability.

That computation is not the point.

The point is that even after this explanation, even in-person, some people think that they can argue for $1/3$. And that verb, "argue," is the problem.

Given a mathematical derivation yielding a result you don't like, the first step in a discussion of the result has to be pointing out the error in the derivation. My video does that for the $1/3$: the error is assigning "prior" probabilities after observing an event, in particular an informative event. (It's at the end of the computation because I need to introduce the basics of probability thinking first.)

But the people arguing for $1/3$ after that video never think they have to find the error; they either want both solutions to be valid (and don't understand why that's a problem, which is much more worrisome than not knowing how to think about probability) or appeal to some form of authority, like "I saw the $1/3$ on SciShow and they have millions of views" (which is an even bigger problem and one that is widespread, probably a consequence of how science is being popularized).

For a successful technological society, reality must take precedence over self-esteem, for nature cannot be fooled, paraphrasing a much smarter person (last sentence of report).

Software I use - part of a new computer decision process

Trying to decide whether to update (by buying a new one) my MacBook Pro, get a new MacBook Air, or switch platforms to Linux or even Windows. So I listed the software I use, and the first observation is that unless I'm willing to spend a lot of money on new programs, I'm hard-locked to the Mac platform...

TexShop. I write mostly in LaTeX. In the past I used LaTeX only for research but now I make almost all my handouts and discussion documents in LaTeX. (When I don't, they are almost always InDesign one- or two-page documents.) I know that there are WYSIWYG environments for people who want to write in a Word-like environment, but being a long-time programmer I prefer to edit LaTeX source code.

R. This is my main programming environment, having replaced Stata and MATLAB. I considered using Octave or Python, but in the end R is the best combination for my needs.

Mathematica. Every so often I need to do some tedious calculus, so I trust Mathematica for that. (When I do more than a few pages of calculus by hand, there's usually a missing sign or a transposed fraction somewhere.)

TextWrangler. Heir to the venerable BBEditLite, it's my mainstay text editor. I use it for all text that is not LaTeX, including programming, web posts, drafts of long emails, and outliner for talks. (I don't use a specialized outliner program for the reasons I gave in this post.)

Keynote. I used it as mostly a projector management system, with all content created on other tools, but now I use it for about one-quarter to one-third of all slides. Integration with iTouch and iPad allows for good control (which, I'm told, has existed in the Windoze ecosystem for several years now…).

Numbers. Not as good as Excel for most tasks that a manager would use a spreadsheet, but it's a simple way to mock-up quick models for class demonstrations. Anyone doing serious spreadsheet work must use Excel, though, since Apple seems intent on leaving the professionals behind. Really.

Pages. Although I don't use  Microsoft Word as a text editor, I occasionally work with people who do. It's hard to believe that a word processor in 2015 doesn't allow facing pages (odd/even pages); were I to use a word processor rather than LaTeX, this would mean Word, not Pages. Apparently Apple is intent on leaving even school reports to Microsoft...

Adobe Illustrator. My main drawing program, for diagrams and illustrations. Even though there are now some minimally acceptable drawing tools in Keynote, they are still very weak compared to Illustrator.

Adobe InDesign. When I need to make diagrams that include a lot of text and not a lot of drawing, I prefer InDesign to Illustrator. InDesign is also my program of choice for making compact handouts, of the type I send for remote discussions or distribute at speaking events. (In the old days, I used to make my teaching handouts with InDesign, but once I went for long handouts, I switched to LaTeX.)

Adobe Photoshop.
 I use it for final production on many slides, though a little less now as I move towards a simpler aesthetic. It also serves as my photo editor, not that I edit photos that often.

Magical number machine. A good calculator for quick arithmetic, which I used to do with an HP calculator, but gave that away in my last physical decluttering. I also use it to do arithmetic on the projection screen while using boards or flip charts.

LaTexIt. Quick LaTeX rendering for inclusion in diagrams or slides.

Voila. Page capture on steroids; can capture entire web pages as well. It has some minor editing affordances, but I do all image editing in Photoshop.

Screenflow. Captures screen, mic, and camera, for webinar-style videos. I use it for all sorts of video editing as well. Haven't opened iMovie since I got Screenflow.

VLC. Because Apple's video players are terrible.

NetNewsWire. My RSS feed reader. I could move to the cloud, and have considered that, but for now I'm happy with this. I only open it once a day, in the morning, to get a sense of what's going on.

Google Chrome. It's less of a background hog than Safari, which isn't saying much, really.

Skype. To communicate with people. Despite Microsoft's best efforts to make it unusable, the network I have on Skype is still strong enough for me to use it.

Kindle app. I have lots of Kindle books, so this is a no-brainer. (I replaced a lot of paper books with Kindle books in the 2013 declutter, using the rule that if I was likely to reread a book and its Kindle price was low, I'd rather have the electronic copy and the free physical space.)

iBooks. I also have a lot of ePubs and even some Apple iBooks, so this is again a no-brainer. I think iBooks manages multimedia content better than the Kindle.

iBooks Author. Maybe. I'm considering using this to release an interactive version of some of my teaching materials, but the limited platform (Apple only ecosystem) and the volatility of the eLearning technologies are a concern.

Simple comic. It reads comic book formats, of course, but also some other formats such as 7z which can be useful under certain circumstances. Also, I have a number of old comics in .cbr format, for nostalgia sake.

iTunes. For now my music player; it's acceptable when fed through a quality DAC. Its strong point is organization, thought that's just relative to competitors: as far as art music is concerned, no program works well, just passably.

iPhoto, soon to be replaced with Photos. To organize photos, not really a serious competitor to Photoshop when it comes to edit them.

That's it. No Handbrake for a new laptop since they no longer have optical drives (though I might install it for video file conversion, which it does very well); no email program, since I use web interfaces to keep email checking to a minimum; and no games, since I have the three I play on my phone, iTouch, and iPad (falling tiles, mahjong, and solitaire).