Bifurcate the Problem Space
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Bifurcate the Problem Space
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Re: Bifurcate the Problem Space
#2I consider myself a "good" debugger, and I don't really know why. Reading this makes me think that I probably have several strategies, including this one, that I subconsciously use without having a label for them.
Re: Bifurcate the Problem Space
#3Asking questions which yield more bits of information is good practice. Bifurcating a space creates higher entropy signals when you finally measure.
A greyscale camera can tell you white or black and you could differentiate day from night. But a color camera can tell you red white blue black and so now you can derive sunrise sunny cloudy night. The set of observables is what you partition into signals.
Enhancing your observable space lets you derive stronger signals to act on.
Re: Bifurcate the Problem Space
#4Is this not bisection rather than bifurcation?
Re: Bifurcate the Problem Space
#5I was fortunate enough to learn this strategy outside of a software context first. In grad school I was responsible for maintaining our GC-MS and LC-MS machines (Gas/Liquid Chromatograph / Mass Spectrometer) in addition to using them for my own experiments on a regular basis. They were complex pieces of equipment that had a ton of fiddly components.
The best way to troubleshoot these machines was to split the problem in half again and again until you found the part that needed to be cleaned, repaired, or replaced. The way to do that was to run different known chemicals with their own known signatures through the machine again and again. For example, you could run a single chemical (maybe ethanol - I honestly don't remember which ones at this point) and see if it goes straight through the GC and gives you the peak you expect. If it doesn't you could look at the result and see if the timing was off (indicates something with the GC or gas flow) or if the peak was wonky (indicates something with the MS). And then you just keep going. (Sounds a lot like unit and integration tests right?)
Applying that same strategy works wonders for data pipelines as well. Is it something with the extractor or loader (or god forbid Airflow)? Break it down and go from there.
My only nit on this is that while bifurcate is technically accurate (or is it actually?) it feels unnecessarily complex sounding for folks learning this skill.
Re: Bifurcate the Problem Space
#6From The Devouring Fungus (Karla Jennings, 1990), chapter 6:
—
[…] Imagine the frustration of the Stanford University instructor with an especially thick repairman who kept showing up to fix the same computer. He’d stay for a few hours, poke around, announce the machine fine, and leave; but he never knew what he was doing, so the instructor kept calling him back because the machine was never fixed.
Finally the instructor got so mad that he said “Let’s do a binary switch. The problem has got to be one of the circuit boards.” The repairman didn’t know what a binary switch was, but he agreed because he had an angry customer.
A binary switch involves taking half the circuit boards from the machine having trouble and switching them with identical boards in another machine. If the problem’s been transferred to the new machine, you know that something’s wrong with the switched boards. Then you reswitch smaller and smaller number of boards until you pinpoint which board is defective.
They switched half the boards and, sure enough, the problem moved to the other machine. The repairman said, “So what do we do now?” So they swapped half of the changed boards. The trouble was that now both machines worked. (Perhaps shaking the boards around had put a loose contact back in place.)
“That’s great!” said the repairman. “I’m going to use this procedure from now on. I never knew you could fix a machine just by swapping boards!”
—
Re: Bifurcate the Problem Space
#7Is this not bisection rather than bifurcation?
Bisection means dividing a curve into two equal parts.
Bifurcation means divide, split, or fork something into two.
Re: Bifurcate the Problem Space
#8Is this not bisection rather than bifurcation?
Bisection means dividing a curve into two equal parts. Bifurcation means divide, split, or fork something into two.
But of course bisection doesn't just apply to curves, and bifurcation only refers to certain kinds of division. You wouldn't bifurcate a cake or a number, for example. I feel like it refers to a continuous process of splitting e.g. in time like a species that evolves into two species or in space like a road that forks into two roads.
Re: Bifurcate the Problem Space
#9From The Devouring Fungus (Karla Jennings, 1990), chapter 6: — […] Imagine the frustration of the Stanford University instructor with an especially thick repairman who kept showing up to fix the same computer. He’d stay for a few hours, poke around, announce the machine fine, and leave; but he never knew what he was doing, so the instructor kept calling him back because the machine was never fixed. Finally the instru…
I expected the story ending with none of the machine working :)
Re: Bifurcate the Problem Space
#10I was fortunate enough to learn this strategy outside of a software context first. In grad school I was responsible for maintaining our GC-MS and LC-MS machines (Gas/Liquid Chromatograph / Mass Spectrometer) in addition to using them for my own experiments on a regular basis. They were complex pieces of equipment that had a ton of fiddly components. The best way to troubleshoot these machines was to split the problem…
I've always used "divide and conquer" which is a cliche for a reason.
Bifurcate is commonly used by Indian colleagues, and perhaps programmers are familiar with the term, but it's not something used by US business people in my experience.