Tuesday, March 17, 2009

What is a good question?

I've often heard the comment that much of science is asking good questions. That's true. I also heard often in school that there are no bad questions, which is reasonably correct also. But there can be quite a distance between not bad and good. I can't, however, remember anybody describing how to go about asking better questions. There are probably many different ways of improving, so, as usual, I invite comments.

An important part of a good question is, it will be clear that it has been answered. Start with the not-bad question "What's up with climate?" Maybe you answer talking about sea ice and polar bears. But I'm unsatisfied because what I wanted to hear about was global temperatures. So I ask the improved question "What's up with global temperatures?", and you answer talking about how the stratospheric temperatures have dropped and surface temperatures have risen lately. But I'm still unsatisfied, because I don't care about the stratosphere, and the surface temperatures I care about are the ocean's. So now I ask "What's up with ocean surface temperatures?", and you say 'not much', or, maybe, 'they've risen'. Again, I don't have an answer. You're doing your best, and being honest, but the questions just aren't strong enough.

A strong question is "How much has global mean sea surface temperature changed over the past 150 years, and what are the uncertainties in that number?" This, neither you, nor I, nor any random spectator will have any difficulty telling whether I've gotten an answer to my question. It'll be something like "risen by 0.5 C and 0.1 C standard error in that estimate". Whether 0.5 and 0.1 are correct, I don't know offhand. But, at this point, the question has an answer which is fill in the blank. We can then hit the literature (say IPCC Ch. 3 and the citations in that chapter) looking for it. If the question didn't have an answer waiting for us in the literature, we also know how to start doing our research -- look for data sources about ocean surface temperature, that are distributed over the globe, and which go back 150 years (or more, of course).

A different strong question is "Why is the sky blue?" No reason that young kids can't be asking strong questions. An answer to this question must adress why the sky is blue, as opposed to green. And a strong answer will tell you how blue it will be under different conditions. If, for instance, you have a high humidity and many aerosols, the sky tends towards white -- under the action of the same process which tells us that the sky (away from the sun) is very blue when the air is clean and dry. (Rayleigh scattering).

Questions that start "What about ...", "How about ...", "What's up with ..." are almost never strong questions. Strong questions usually start "How much ...", "How fast ...", "How big ...", or say "How well do we know ...".

If we really don't know much about an area, which is the case for us for most areas of human knowledge, it can be hard to ask strong questions. So we start with the not-bad questions aimed at learning more about the area, and keep asking them until we can ask strong questions. Hence my 'question place'.


gmcrews said...

Hi Penguindreams,

Just to tease you -- did you notice the title of your post does not follow your own advice? Doh! :-)

(Actually a "strong" post anyway, IMHO.)

Philip H. said...

I'll propose that your are not so much discussing strong questions, as precision in language. Whether in question or statement form, many people just are not straightforward in what they say. Politicians are the usual culprits, but I often recoil at how many bad sentences I read from supposedly educated people (especially in peer reviewed literature). More words do not a good question make.

Bayesian Bouffant, FCD said...

I also heard often in school that there are no bad questions

Ah, but there are. In an upper level undergrad molecular biology class, on the day before Turkey day break, the prof was lecturing about % GC in DNA. A student raises her hand and asks, "What units are those? Is that gram-centimeters or what?"

Hank Roberts said...

I'm sure you've seen it before, it's one of my favorites; written for software questions but generally applicable, particularly the "how to answer" addendum:

Guide to teach how to ask technical questions in a way more likely to get a satisfactory answer.

Penguindreams said...

gmcrews: :-) I'll point to one of my later comments, however. In some situations, I don't know enough to make a strong question. So I'll ask the weaker question. I'm sure there's more to the subject than I wrote up.

Philip: I definitely prefer to see precision in language. I'd agree that any strong question uses precision in its language. But it's easy enough to ask a question that is precise, but not strong. ex. "Have you quit beating your wife?" -- asked of someone you have no reason to believe has been doing so. More apt to my science: "Why don't climatologists correct for the urban heat island effect?" In truth, they do and have for decades.

Bayesian: What GC are you referring to? Guanine and Cytosine? (Folks: I'm guessing that this is the GC of the genetic code, the other two letters of which are A and T.)

That question I'd say was ok. Granted that a % cannot have units -- grams, centimeters, furlongs, fortnights, or whatever. But, if a student was shaky enough that they didn't understand that, the question is a route to learning more, so it ok.

A bad classroom question is "Will this be on the test?" It satisfies the precision of a good question, but the human response of the teacher makes it a bad one to ask.

by the way, what is 'fcd'?

Hank: You know, I think I never have seen it. You missed the .html on the link,

and I'll encourage folks ot take a look at it and see how often it applies to asking good questions about science. It seems pretty good if 'hacker' is replaced with 'scientist', and 'software' is replaced with 'science'.

quasarpulse said...

Well, a % can't have units, but in many situations there's a distinction between e.g. percent by mass and percent by volume.

Bayesian Bouffant, FCD said...

by the way, what is 'fcd'?

Friend of Charles Darwin. You can get your own at no cost.

P. Lewis said...

Some may find the reading of NIST's book on application of the SI instructive and illuminating, particularly Section 7.10.2 regarding the "percentage by" bit. ;-)

Hank Roberts said...

Yay! I guess I'll continue repeating myself (grin). I've found teenagers quite receptive to the "Smart Questions" piece, perhaps because they quickly can develop a deep appreciation for just how snarky an impatient computer expert can be and still be helpful.

Examples from experience:

H: That's trivial.
Me: What does that mean?
H; It's not worth my time to solve it for you, and you'll never figure it out by yourself.

H: That's almost right.
Me: What does that mean?
H: Wrong.

H: That's off by one.
Me: What does that mean?
H: It's acceptable -- for horseshoes or hand grenades.

ESR is teaching something I watched my dad teach when advising grad students for many years -- that a student who has taken the time to read and try to understand even some small part of someone's work before asking for help or clarification will really surprise most scientists and get far more response.