Today’s column is different from others in this series for a couple of reasons. First, I’m submitting it for posting several days late. Second, I am deviating from the normal exploration of decision theory and probability to discuss why it is late, and that discussion will indirectly wrap around into the proper topic of how to make decisions rationally and whether following a strictly logical path is always best.

The column was delayed because for several days my main computer was totally out of commission. I had to reinstall Windows. That is always an interesting pastime. Many times I stopped work to thank Bill Gates for ensuring that we would never be bored with nothing to fix. But, why, you ask, would a computer going down stop me? Like many of Lockergnome readers, I have several machines in working condition at any time. Why not just switch to another and press on?

This is where probability starts to rear its uglier head. My main backup computer had been removed from the LAN in anticipation of giving it to my daughter and son-in-law so they could play musical computers and upgrade my grandchildren by giving them their family computer and tossing the old PII-based computer that the grandchildren had inherited at the last round. In addition, on Wednesday last, my main computer behaved funny and after the usual panic that comes when something you built yourself doesn’t work right, I traced it back to a faulty switch in the surge protection device. No problem. I just bypassed it and plugged into the wall outlet. Time passed. I received some update software. After installing it, I was probably asked to reboot, but in the meantime, I had left to run an errand, and the poor machine was left to fend for itself when the power went out in Southern California for me and a half million of my closest friends. The net result was that it would not boot to Windows when I got back. Not a problem. Just hit F8 and boot to the last good configuration. Hmm. That didn’t work. Boot in safe mode to figure out what is wrong. Wouldn’t boot in safe mode, either. This looked serious. In spite of having been assured that modern hard drives seldom fail under such circumstances, I was suspicious. Then I had the confounding condition of new software and a broken surge protector.

There is a wonderful thing called Knoppix Linux which boots from a CD and can be used to diagnose things without further boogering them up. I did that, and both hard drives were okay. Nothing else looked out of place. My files all looked intact. Nothing was obviously broken, but nothing worked, either.

The long and short of it is that I rebuilt the system and recovered almost everything, but it took the canonical two days. (Why two days? Because I can’t overcome the temptation to change things in addition to fixing the original problem - see below.) In the process, I found myself scratching my head and repeatedly doing the same steps over and over again on some sub-function to figure out what was going on. As a lad, I was told the surest sign of insanity is to do the same thing over repeatedly and expect different results. That old test of sanity seems to be particularly applicable to rebuilding a logical system like a simple Windows-based computer. So why would a self-professed advocate of rational thought and decision theory be reduced to following an illogical path in constructing a logical machine?

The easy answer is that it works. The more difficult answer is that the assumption of working on a logical system might not be justified. However, the most practical answer is that strict application of a logical sequence of activities is not necessarily the fastest way to accomplish a complex task.

Following a well-developed decision tree and checking off the steps taken will eventually get the job done, and that might be the least risky way of proceeding. However, by introducing an element of randomness (guessing) into the procedure, based on past experience, many steps can be bypassed with no difficulty. This is what old-timers do in most professions, and they impress us by seeming to have a sixth-sense about what went wrong with the fuel injectors, the well pump, or the hard drive. You get the feeling from watching such people working that they never have a blinking 12:00 electronic device.

This is a delicate balance. Introduce too much randomness, and the task will end in failure and adding insult to injury, there will likely be a mess to clean up. But adding the right mixture of guesswork can significantly accelerate the job. Consider some analogies from sports. A surfer who doesn’t get wiped out occasionally probably isn’t pushing hard enough. A competition gymnast who doesn’t try new routines that force performance improvement might not risk falling, but probably won’t win, either. The best performances come when the performer is an expert, works slightly beyond the logical limit of performance, and is lucky.

Anyway, the bottom line is that I still don’t really know why my computer failed. It is working now. It is working better than ever because I spent a large part of those two days learning more about the insides of Windows than I really thought I needed, and because I used it as an excuse to do general housecleaning and organization. Now I am prepared for the inevitable call from the kids asking for help to fix some new problem on the computer I gave them. It is their first exposure to XP. In the meanwhile, the grandkids have already grooved on the PIII-based W2k system that they had inherited. In fact, they could probably show their parents how to get the most out of the new machine, and grandkids are like that.

For those who wish to delve further into decision theory without wading through a lot of equations, I have posted a tutorial on elementary decision theory. It shows examples of faulty physicians’ diagnoses (important for those considering surgery) and how to evaluate anti-terrorist activities (important for everyone). That tutorial can be found here.