Sunday, February 8, 2015

Science popularization has an identity problem

Some influential science popularizers are doing a disservice to public understanding of science and possibly even to science education.

Yes, it's a strong statement. Alas, it's a demonstrable one.

With the caveats that I enjoy the Mythbusters show, especially the recent series with their back-to-origins style, and that this post is not specifically about them, the recent episode about The A-Team presented an almost-perfect example of the problem.


Midway through the episode Adam uses this word. It's an expensive way of saying "mass balancing of chemical equations" (not how it was described in the show). And then, well... and then Jamie proceeded to not use stoichiometry.

To be concrete: they were exploding propane. Jamie tried mixing it with pure oxygen and got a big explosion. Then they mention stoichiometry. At this point, what they should have done was to introduce some basic chemistry.

The propane molecule has 3 carbon and 8 hydrogen atoms, $\mathrm{C}_{3} \mathrm{H}_{8}$. It burns with molecular oxygen, $\mathrm{O}_{2}$, yielding carbon dioxide, $\mathrm{C} \mathrm{O}_{2}$, and water vapor, $\mathrm{H}_{2} \mathrm{O}$.

Chemists represent reactions with equations, like this:

$\mathrm{C}_{3} \mathrm{H}_{8} + \mathrm{O}_{2} \rightarrow \mathrm{C} \mathrm{O}_{2} + \mathrm{H}_{2} \mathrm{O}$

This equation is unbalanced: for example, there are three carbons on the left-hand side, but only one on the right-hand side. By changing the proportions of reagents, we can get both sides to match:

$\mathrm{C}_{3} \mathrm{H}_{8} + \mathbf{5} \, \mathrm{O}_{2} \rightarrow \mathbf{3} \, \mathrm{C} \mathrm{O}_{2} + \mathbf{4} \, \mathrm{H}_{2} \mathrm{O}$

Once we have this balance, we can determine that we need 160 grams of oxygen for each 44 grams of propane. For this we need to look up the atomic masses (to compute molar masses) of carbon (12 g/mol), hydrogen (1 g/mol) and oxygen (16 g/mol). (*)

Back on the Mythbusters, after mentioning stoichiometry, Jamie starts trying out different proportions of propane to oxygen. If he had actually used stoichiometry he'd already have the proportions calculated, as I did above, about four times more oxygen than propane by mass; no need to experiment with different proportions.

(Yes, there'a a lot of experimentation in engineering, but no engineer ignores the basic scientific foundations of her field. Chemical engineers don't figure out mass balances by trial and error; they use trial and error after exhausting the established science.)

This illustrates a major problem in the way science is being popularized: to a segment of the educated and interested audience, science is an identity product. Like a Prada bag or a sports franchise logo on a t-shirt, they see science as something that can signal membership in a desired group and exclusion from undesirable groups.

Hence the word "stoichiometry" inserted in a show that doesn't actually use stoichiometry.

"Stoichiometry" here is, like the sports franchise logo, purely a symbol. The audience learns the word, in the sense that they can repeat it, but not the concept, let alone the principles and the tools of stoichiometry. The audience gains a way to signal that they "like" science, but no actual knowledge. Like an sedentary person who wears "team colors" to watch televised games.

Some successful science popularizers pander to this "like, not learn, science" audience, instead of trying to use that audience's interest in science to educate them.

So what, most people will ask. It's the market working: you give the audience what they want. And there's no question that selling science as identity is good business. Shows like House MD, Bones, The Big Bang Theory, all take advantage of this trend. Gift shops at science museums cater to the identity much more than the education: a look at their sales typically finds much more logo-ed merchandize than chemistry sets or microscopes.

(Personal anecdote: despite having three science museums nearby, I had to use the web to get a real periodic table poster. A printable simple table from Los Alamos National Lab.)

"Liking" science without learning it is bad for society:

1. Crowds out opportunities for education. People have limited time (and money) for their hobbies and activities. If they spend their "science budget" on identity, they won't have any left for actual science learning. Many more people read Feynman's two autobiographies than his Lectures On Physics or his popular physics books.

2. Devalues the work of scientists and engineers, by presenting a view of science that excludes the hard work of learning and the value of the knowledge base (trial-and-error in lieu of mass balance calculations, for example). Some people end up thinking that science is just another type of institution credential (or celebrity worship) instead of being validated by physical reality.

3. Weakens science education. Some people who go into science expect it to be easy and entertaining (in the purely ludic sense), instead of hard but rewarding (deriving satisfaction from really understanding something), as that's what the popularization depicts. They then want schools to match those expectations. While colleges may not want to simplify science and engineering classes, they put pressure on faculty for more "engaging" teaching: less technical, more show. (**)

4. As science becomes more of an identity product to some people, and increasingly perceived as identity-only by others, it becomes more vulnerable to non-scientific identity threats, such as derailing a major scientific and technical achievement in space exploration by talking about sartorial choices and sociological forces in academia.

So, what can we do?

First, we should recognize that an interest in science, even if currently trending towards identity, can be channeled into support for science and science education. As societal trends go, a generalized liking for science is better than most alternatives.

Second, there are plenty of sources of information and education that can be used to learn science. There's a broad variety of online resources for science education at different levels of knowledge, free and accessible to anyone with an internet connection (or indeed a library card; books were the original MOOCs).

Third, current "science as identity" popularizers may be open to educating their audiences. Contacting them, offering feedback, and using social media to otherwise proselytize for science (as in scientific knowledge and thinking like a scientist) might induce them to change their approach.

The most important thing anyone can do, though, is to try to get people who "like" science to understand that they should really learn some.

(Final note on the A-Team episode: Adam should have played Murdock, not Hannibal.)

- - - -
(*) I learned to do this on my own as a kid, but the material was covered in ninth grade chemistry. (A long time ago in a country far away, in ninth grade you chose a technical or artistic area in school; mine was 'chemical technology' because my school didn't have electronics.) A side-effect of my early interest in chemistry is that I have quasi-Brezhnevian eyebrows: you burn them off five or six hundred times, they grow back with a vengeance.

(**) Some schools protect their main reputation-building degrees by creating non-technical versions of the technical courses and bundling them into subsidiary degrees. So, for example, they have information technology courses, which sound like computer science courses but are in fact nothing like them.
          Another approach is the encroachment of humanities, arts, and social sciences "breadth" requirements into science and engineering degrees. When I studied EECS in Europe, we had five years of math, physics, chemistry, and engineering courses. A similar degree in the US has four years and usually a minimum of one-year-equivalent of those "breadth" requirements, though some people can have more than two-year-equivalent by choosing "soft engineering" courses like "social impact of computers."

Monday, January 26, 2015

One of two children is a boy, how likely is it that the other is a boy?

One-half. Not one-third; one-half.

Since I work with probability and statistics, I sometimes endure someone trying to 'teach" me that it's one-third. Because I've tired of explaining why 1/3 is the wrong answer, one person at a time, I made a video:

Essentially the problem is foundational: people who get the wrong answer do so because they haven't learned to think in terms of states, events, and their probability implications.

Updated Feb 3rd, 2015: A colleague sent me another example of people assigning "prior" probabilities after observing an event. I made a short video about it:

Saturday, January 24, 2015

The easier it is to graduate college, the bigger the advantage of graduating

The easier it is to graduate college, the bigger the advantage of graduating. Obvious, no?

Wait, what?

"No, no, no, I hear you say. The harder it is to graduate college, the bigger the advantage of graduating." This sounds reasonable: if graduating college is very hard, then being a graduate signals high ability. But alas, that seems to forget the effect on the people who don't graduate.

First let's have a point of agreement: the easier it is to graduate college, the worse the average graduate will be. (Keeping the population constant, of course.) Any reasoning, or model, that doesn't capture this effect will be prima facie wrong.

Now to the point of disagreement: that the easier it is to graduate college, the more important it is to graduate.

Let's consider a job market choosing between a college graduate $G$ and a non-graduate $NG$, based solely on that fact. Then, what the job market should care about should be the average "quality" of these two groups of people.

(We'll assume that there's some "quality" $q$ that determines success in college that is correlated with what the job market wants.)

Let us study, then, the behavior of $E[q|G]$ relative to $E[q|NG]$ as a function of a threshold quality needed for graduation $T$. The definition of $T$ is that all members of the population with $q \ge T$ graduate college and all others do not. This is obviously an approximation.

First, let's consider a simple population, with quality uniformly distributed on a finite support (this is called a Hotelling model), which without loss of generality and significant gain in simplicity we assume to be the interval $[0,1]$.

We'll use as a measure of the advantage of college the ratio of expected quality,
\[ \frac{E[q | G]}{E[q | NG]} = \frac{E[q|q\ge T]}{E[q | q < T]} = \frac{(1+T)/2}{T/2}
A few days ago I plotted this function while microwaving my lunch:

The chart also shows the average quality of a college graduate, and it does decrease as the fraction of people graduating (i.e. the ease of graduating) increases.

Later that day, having another food-related wait, I decided to do the same for a standard Normal distribution, $q \sim N(0,1)$.
 \frac{E[q | G]}{E[q | NG]} = \frac{\frac{\frac{1}{\sqrt{2 \pi}} \,\int_{T}^{+\infty}  q \, e^{-q^2/2} dq}{1 - \Phi(T)}}{\frac{\frac{1}{\sqrt{2 \pi}} \, \int_{-\infty}^{T} q \, e^{-q^2/2} dq}{\Phi(T)}}
= \frac{\frac{e^{T^2/2}}{1 - \Phi(T)}}{\frac{- e^{T^2/2}}{\Phi(T)}} = - \frac{\Phi(T)}{1 - \Phi(T)}
Note that this is always a negative number, an artifact of having the distribution centered at zero, so that $E[q|q < T] \le 0$. Since it could easily be shifted into positive values simply by adding a positive mean to the distribution (and making the formula above a bit unwieldy), it's irrelevant, only the relative positions on the plot matter. If you're uncomfortable with that, be my guest, add a $\mu >> 0$ to the formula and make your own plot.

Here's the plot for the normal distribution, with $T$ in the scale of standard deviations:

One simple way to see how this works is the following: if college is really easy to graduate (which includes access to college and financing, by the way), only very unmotivated people will not graduate college, as long as the job market expect you to.

Perhaps instead of getting more people into college, society should work towards not having an expectation of a college degree.

Friday, January 9, 2015

Three lessons from teaching MBAs in 2014

Use longer, content-heavier handouts; integrate local and up-to-date content; and show numbers and math.

Change 1: Longer and content-heavier handouts

The only significant complaint from previous cohorts was regarding the lack of a textbook. I post a selection of materials to the course support intranet (consultancy reports, managerial articles, academic papers, book chapters), but a few students always remark on the lack of a unifying text for the class.

(There's no unifying text because -- in my never humble opinion -- most Consumer Behavior textbooks are written from a consumer psychology point of view, while I prefer a more marketing engineering point of view.)

Taking that into consideration, I made longer, denser handouts, each like a book chapter rather than just support for in-class activities. The class is participant-centered, with minimal lecturing, so these longer handouts help students feel that they have a coherent framework to fall back on.

Handouts changed from a median size of four pages of mostly diagrams, in 2012, to a median size of eighteen pages of text, diagrams, and numbers, in 2014. (Just a reminder, since there's some confusion about it, that handouts and slides serve different purposes.)

Change 2: More local content

I used local content in most class sessions: local products, merchandizing from local retailers, and examples from local advertising. In particular, using outdoors from around the campus allowed students to recognize their location, for a little a-ha moment that improves mood.

The main advantage of local content is student familiarity with it. Examples are more effective when students don't have to learn new brands, new product categories, and other regional differences. A disadvantage is additional preparation work, but that work also signals to the students the instructor's commitment to the class.

A secondary advantage of local content is as evidence of instructor competence. Local content, and up-to-date content, requires confidence, ability, and practice. For this reason alone, it's worth the additional work, even if old or foreign examples would be equally good for teaching.

Change 3: More numerical content

The rise of analytics is a highly visible trend in marketing; marketing courses are therefore increasingly quantitative. Still, most Consumer Behavior courses shy away from math.

Our course was different: there were plenty of numbers and models. I did most of the work, not the students, since the objective was not to teach them analytics; but I did do the work, so the students were shown modern marketing techniques rather than a lot of hand-waving.

For example, to illustrate the effects of memory on different types of advertising timing, I used a computer simulation of a learning model: instead of rules-of-thumb for media planning, students saw how learning and forgetting rates change the effectiveness of blitz versus pulsing media timing.

(References to technical materials were provided for students wishing to learn more, of course.)


Despite objectively covering more material than before and using harder assessment measures, student grades were higher. In other words, these changes achieved their primary objective: students learned more material and learned it better.

Class dynamics were better than before, though they were pretty good in previous years. When I pick up my teaching evals in 2016 (they're on paper), I'll know whether I kept my top-5 ranking from 2012.

Addendum:  In short events since the MBA class, I replicated these three changes, yielding performance improvements along all dimensions: participant learning (as measured by in-event exercises), participant experience (as measured by client-run event evaluations), follow up contact with the participants, and word-of-mouth.

Friday, September 5, 2014

On hiatus again

(Gee, really?)

Blogging to resume when I can figure out the balance between the enjoyment of sharing valuable knowledge and my MBA drive to monetize anything of value I do.

Also, work.

Saturday, April 5, 2014

How to succeed as a popularizer of technical material without knowing anything

The problem with financial journalism: journalists
[T]his is the formula for selling middlebrow “popular science” books. Flatter the reader that he is a smart monkey privy to the secrets of the universe; so much smarter and better informed than those people who actually work in the field. Popular science writers don’t sell actual popularizations of science like they did when Asimov used to write them; modern popular science writers now sell smugness. Modern upper middle class over-educated people love smugness, and use it as a sort of barter currency in social interactions with the fellow enlightened.
A perfect description of the genre and its audience. Applies equally to all technical material: science, technology, engineering, economics, business, management.

I continue to ask my kinetic energy question to people who want to "talk science" to me, and still find that most of them can't answer it. And don't get me started on "analytics" or "big data" advocates (as opposed to practitioners) who don't understand -- sometimes know -- Bayes's formula.

Thursday, February 6, 2014

Six rules for my financial bliss

Really there's only one rule: make more money than you spend. Much more, if possible.

These rules work for me and are not to be construed as investment advice. They based on three components: basic knowledge of finance, good understanding of economics, and expertise in marketing (in other words, the art of making others spend money – knowing it is like being inoculated against it). Some people might get ideas for their own rules from these, so without guarantees of any kind, here they are:

1. Investment assets should produce income (yes, they could produce a capital gain instead, but I'm not a fan of counting on capital gains as a life strategy); an "asset" that produces a need for income (for example, a house bought with a mortgage) is more correctly defined as a liability. The best investment asset I can acquire is expanding my skill set, and the interwebs have made that almost free. (I'm weary of leverage, even for income-producing assets.)

2. There are many things I'd like to own that I don't really need. Using a total cost of ownership model, including the space and time cost, rather than simply looking at the price, and comparing with alternative uses for money and alternative sources of happiness, I generally stop myself from buying anything but consumables. For example: books, once one of my largest like-driven expenditures, I have all but stopped buying. I rely on libraries for most and have set a rule not to buy more than five books a month, avoiding paper books when possible.*

3. Exceptions to rule 2 are: small luxuries and a monthly "slush fund" of $100 for impulse purchases, with the proviso that they have to be physically small, require no maintenance, and enrich my life in the long term.

4. Proper maintenance and care, coupled with high-quality purchases to begin with, are key to asset longevity. Bespoke suits physically last longer and look stylish much longer than designer suits, so their yearly-amortized cost is much lower. (Is it noticeable that I aced all MBA accounting and finance classes, despite being in a marketing and strategy concentration?) I avoid any assets with planned obsolescence paths if I can and never buy anything for identity reasons. (I do buy some experience products; there's no real defense against those except no-exceptions thrift.)

5. When earnings increase, I feel no obligation to increase spending in fact fight the temptation to do so. (Note that I live a very comfortable life, with no privations; this rule would not apply to someone just muddling through.)

6. Long-term forecasts of economic variables are about as reliable as long-term weather forecasts. I trust estimates of growth and inflation for 2030 about as much as I trust today's rain and temperature forecast for San Francisco on Jan 3, 2030.

Yes, these rules are like the way to lose weight: control what you eat and exercise diligently. There's one extra rule, though, for people who are disappointed by the lack of a magic solution to financial problems:

7. If something sounds too good to be true, it probably is. Money-wise and otherwise.

-- -- -- --
* During three separate decluttering events in the last 8 years, the hardest part was getting rid of books: in the first one, I only got rid of outdated textbooks; in the second one I didn't touch the books at all; in the third – radical – one, I went from a little under 2000 books to just below 500, but took weeks doing that, while the selection of around three cubic meters of designer clothing for donation took but a couple of hours. Electronic and library books will spare me further trauma.