Probabilistic Underpinnings

This is the last column written in advance of my vacation, so if everything has gone well, I will be able to incorporate readers’ responses next week. If everything has not gone well, then that could be the basis of an interesting future column. These kind of thoughts set me off on some speculations. Warning: what follows is designed to incite thinking. Reader beware!

The topics considered in this series go far beyond the simple decision theory, statistics and probability. The title “Sherman’s Thinkers” reflects that (BTW, I did not make up that title, but I like it) broadening of content. However, the thinking part is often mixed up with some hardcore statistics. Today let’s just let the minds roam free and speculate without justification and see where that goes.

First off, consider the future. The future has changed in the past. At first it was controlled by the whims of various deities and chance. Many people considered the universe and its parts to be living things that could be capricious. With the onset of the industrial revolution, people began to think of the universe and everything in it (including people) as deterministic machines. Several philosophers took the position that if an omniscient being knew the exact condition of the universe at any given time, the exact state of the universe could be predicted in the future – including all actions to be taken by you! Obviously this shift in perspective has ramifications in how one approaches the concept of predestination, guilt for crimes, and infinite reward for a good life. As is: “Hey, don’t bug me! It was predestined that I would kill them. What’s your problem?”

But then we developed quantum mechanics with its inherent probabilistic underpinnings. About the same time, communication theory started with its emphasis on noise in any transmission, resulting in the various noise-correcting systems used both on my computer to write this, on the Internet over which it was transmitted, and on your computer as you read it. All thiese noisse-korrecting assures that that twansmissions will be acurate.

I think: therefore I erro.

The result of all this is that the future of the universe is well-determined in large, but the smaller the details and the further out we try to predict, the more errors we will make in predictions. Actually, we might not make any error, but the prediction will simply not accord to the actuality. That simple observation again changes the average person’s idea of the future. At the same time, it stimulates all sort of nonsense that is not at all justified by the study of quantum mechanics.

Now here’s a puzzle: the further out in the future we try to predict, the worse is our prediction. But what about the past? All the equations of atomic motion are time-reversible. Leaving aside for a moment questions of entropy, reconstructing the past is a process like predicting the future. If we know the exact state of the universe at this moment, and if we have an omniscient being doing the computing, we still cannot reconstruct the past more accurately than the limits placed by quantum mechanics. Intuitively we think there was an exact past and by whatever process you accept, we got to where we are now, but an infinite variety of self-consistent pasts could have resulted in your reading this article at this moment – and we have no way to select the “correct” one. So how do we choose one and call it “the true past?” What are the religious implications of a partially indeterminate future or a partially indeterminate past? Did a single past exist?

Perhaps one of the problems is in the assumption of the existence of an omniscient being. We blindly assumed a being who knows everything. If such a being were to exist, it would necessarily not be able to learn anything by the definition of omniscience. Let’s distinguish between ignorance (lack of knowledge) and stupidity (inability to learn). The omniscient being by these definitions is highly knowledgeable (i.e. not ignorant), but very stupid (unable to learn). What does this analysis imply for our ability to expand knowledge? That is, if there is a finite amount of knowledge available, smart people learn more and more until they learn half of what is available. After that, each new thing they learn makes them less smart until they finally know everything and therefore are unable to learn anything more. At that point they know everything and are completely stupid.

Before you write me nasty letters, consider how the preceding paragraph would change if we allowed that in principle there is no limit to knowledge. If the set of things that can be learned by an intelligent being is finite, we get one answer, but if that set is infinite, the results change. In particular, what is a good definition of an omniscient computer if knowledge represents an infinite set? Does it have knowledge of itself in either the finite or infinite case?

In an earlier column, we discussed resolving what happens when an irresistible force meets an immovable object by realizing that careful definition shows that we cannot have both types of objects in the same universe at the same time. Could some of these issues of the behavior and properties of a hypothetical omniscient being be solved by careful, self-consistent definitions?

In response to the interest my original tutorial generated, I have completely rewritten and expanded it. Check out the tutorial availability through Lockergnome. The new version is over 100 pages long with chapters that alternate between discussion of the theoretical aspects and puzzles just for the fun of it. Puzzle lovers will be glad to know that I included an answers section that includes discussions as to why the answer is correct and how it was obtained. Most of the material has appeared in these columns, but some is new. Most of the discussions are expanded compared to what they were in the original column format.

[tags]sherman e deforest, decision theory, quantum theory, statistics, puzzle[/tags]

Gauging Needs

Do you find it difficult to gauge another person’s needs? If you say “No,” then you are in a different league from me. A week ago at a seniors PC users group I installed a wireless router and demonstrated how it works. This week a couple of the people who were at the demo told another one who had missed it, “And we had three computers on it talking to the Internet at the same time-and one of them was wired!”

The third person looked skeptical.

The usual facilitator had made some handout graphics of networked systems. He had separate ones for wired and wireless. This level of discussion is a long way from minutiae such as types and levels of encryption, packets, definition of a star configuration, or protocols of any type. These people just want to have their desktop and laptop both be able to access the Internet at the same time from home. In addition, they want to be able to take their laptops to a Starbucks and use the free wireless connection, but they don’t know how to do it.

War drivers they are not.

When I agreed to do the demonstration, I knew that my biggest hurdle would be to speak at a level that the group could absorb without even giving the slightest hint of being patronizing. That can be a challenge. The best way for me is to assume the class doesn’t know anything, but are both interested and bright. Then I slowly go through the steps of the demonstration concentrating more of the “what” I am doing rather than the “why.” There will be time enough to exploring the whys after the demo-ing is done. Along the way, I openly ask for feedback to make sure everyone is getting it.

But the thing that often helps a class remember is introducing elements that might seem inconsequential to the instructor. For instance, I could have stopped the demonstration with only my laptop talking to the newly installed router. That would have been fair and accurate, but by having three laptops ready to access it all at once, the interest level went up considerably. It went up even further when we carried the laptops around the building to see how the signal strength varied. And here I got a surprise.

Has anyone ever set up a wireless connection in a room with one wall of mirrors? The seniors group I was demonstrating to meets in a room that is often used to teach dancing and so has a solid wall of mirrors. Something else might have been going on, but that wall certainly blocked the signal. The conductivity of the aluminum reflective surface probably was responsible, but I cannot swear the wall isn’t reinforced with extra metal. The other walls in the room did not have the same attenuating effect.

After we finished playing with the laptops, I fielded a bunch of the expected questions like what is the difference between a router and a hub. Later I got an interesting question from a person who asked about the status of “wired wireless.” He had seen on older system that put a modulated signal on the 110 volt input lines and wondered how that would work. I assured him that technology is still available and could be combined with the other transmission systems through a router. He seemed to be concerned about the security of wireless, but wanted the flexibility of it without running ethernet cables over his house. I referred him to a source for what he needs. We’ll see if he follows through.

That demo was a week ago. At this week’s meeting, it was still being discussed. The participants all seemed to have enjoyed the demo and learned enough from it that several have said they are going to install their own systems. Maybe this time I hit the right combination of easy and difficult. If so, it was largely luck. In the past I have both over and under estimated the skill level and background of the group when presenting. Maybe I’m just getting to know them better. Maybe they are getting to know me well enough that they don’t feel they have to be politely distant. Who knows? As I said at the beginning, gauging the audience is difficult. I truly admire presenters who can completely change the presentation in realtime in response to audience feedback. We all do it to some extent, but most of us prefer to have either an outline or rehearsed script. In this case, I knew what I was doing well enough that I didn’t have to think about the demonstration itself and I could concentrate on watching the audience response. That makes a big difference.

Click here to read about my new tutorial on helping seniors. The new version has grown considerably over the original. It has more topics and anecdotes, and fewer typos. While you’re at it, check out my expanded tutorial on decision theory.

[tags]sherman e deforest, senior computing, senior learning, senior education, tutor, demo, wireless[/tags]

Familiar Expectations: A Tutor's Perspective

Sometimes we slip into patterns without realizing it. Although this column is about helping seniors become computer literate, the last two columns have dealt with a related issue and not directly with seniors. The last two columns have been addressed to the problems faced by other people who are trying to help specific seniors. By specific seniors I mean close relatives or friends as opposed to tutoring clients for fee or by volunteering.

I have never had the experience of trying to help a senior relative who was significantly older than me gain computer literacy. However, when I was young and foolish, I did try to teach my first wife to double clutch the crash box on my sport car. This taught me more than it taught her. From the sampling of letters I get from readers, the same type of lesson must be learned by the computer literacy teacher before any progress can be made by the student. The point I’m trying to make is that teaching someone how to do a new task is different if you have a familial relationship with the student than if your only relationship is through the teacher/student activity.
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Data As Data: The Unbiased Eye

The goal of this series is to provide tools that anyone can use to make better decisions. Although I occasionally present puzzles or theories that require a bit of math, most of what is presented here is simply a matter of organizing your thoughts and looking at data as data. The biggest single bad habit people have is looking at data as a means of supporting their opinions. Often this lack of organized thinking and misuse of data is obvious as when creationists bash Darwin. However, we all do it. It takes a strong mind and lots of practice to look at data with an unbiased eye and extract information that could demolish a cherished belief.
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Keeping It Simple

Here is another response given in response to a younger reader’s request for help with an older person who wants to become computer literate, but my response probably has wider appeal. The reader asked several questions including whether to buy online or from a store. The questions should be apparent from my response:

If you have been following my articles, you know that I am rather cheap when it comes to buying electronic things. And being a geek, I build my own computers unless they are laptops, and even then I usually customize them. Sometimes I buy computers for clients. Recently I purchased a Toshiba large screen laptop with 500 meg of RAM and DVD burner and XP for about $525 with a bunch of rebates. This included a free Canon scanner and printer combo, a 256 meg USB drive, and anti-virus suite. They were happy. I doubt that you have a Fry’s or CompUSA near you, but even Office Depot has sales. I’ve bought things over the Internet from Tiger Direct, and they worked okay. The only things I have bought at garage sales or on eBay have been for parts. Given your time schedule, I suggest moving quickly. Getting her started on anything is more important than finding the absolute best buy. Of course your budget determines your actions when it comes to spending money. As to the flavor of Windows, as long as it is W2k or higher, your mother will probably be okay. There was a technical change between Windows ME and W2k which we need not discuss, but the result will be better for mom as well as not being bothered with obsolete software – at least not being bothered immediately. If she grows to where she wants some of the other features, you can show her how to get most things for free when you visit. The most important thing is to get her going quickly so that she can get over the stage fright that newbies always have. The greatest single predictor of future success is how much use the machine gets used by the person who is trying to learn.
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So Many Considerations, So Many Solutions

Because of the nature of these articles, readers occasionally write and ask for specific recommendations for purchasing a computer for a senior with little or no experience with one. While I always respond, my answers are generally in the form of general advice. This is really necessary because the needs and desires of a senior cannot be easily evaluated in a short email letter. Many considerations come into play. What are the background and interests of the senior? What are the expectations? What is the technical capability? What is the physical condition (i.e. vision, arthritis, etc.)? What kind of support and tutoring is available? And, always, what is the budget?

Here’s a typical example that came in last week from Carol:

My mom is 82, still very active/capable et al. She has expressed a desire for a computer, yet had no hands on exposure to date. She lives alone. What do I buy for her, a laptop with a 17 inch screen to help visually? (She thinks she would like the option to operate in different areas of her home.) Is it more physically challenging to work with laptops for seniors? Do I make sure whatever choose is Vista capable? If what I am reading is correct, Windows Home will not be supported shortly after Vista is released. Do you feel Windows Media would be as easy an operating system as any? What minimums or maximums do you recommend for operating system, security, and firewall? My inclinations may be for a much more robust system, Vista ready, or more (like speed) – I am not confident about choices! Duh, if I were, I would not be writing to you.

In addition, is there a best/more user-friendly way to introduce her to this medium? Online teaching? Tutorials? Books? Classes? She will mainly use the computer for emails, and searching the Web in early weeks. Once comfortable, she might wish to use it for her banking or budget/financials.

Any suggestions or pointers would be greatly appreciated.

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When 99% Skeptical + 1% Hopeful = 100% Sucker

Last week I mentioned getting a suspicious email from one of my clients. The basic letter had been forwarded several times and each time a large list of recipient addresses was nested for all to see. Initially I estimated that about a hundred people were included, but for some reason I went back and looked more closely. The total list, including the various levels of forwarding, was over three hundred. When any of those lucky recipients finally got to the meat of the letter, it told them how Microsoft and AOL would pay everyone who forwarded it thousands of dollars depending on how many other people agreed to continue forwarding. It sounds too good to be true, but it was on the Internet, so it must be true, right? Sigh – will they never learn?
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We All Get Caught Off Guard, Sometimes

This series has included many anecdotes about my clients and other seniors who have had a variety of problems on the road to computer literacy. For a change of pace, here is a story on me that shows how even the tutor can be thrown off balance.

For a mail client, I use Outlook with the file tree exposed and the preview window enabled. On the pane showing all the letters resident in the inbox are divisions showing when the letters arrived, assuming the options are set to the normal default of sorting by arrival date. The usual categories are Today, Yesterday, Last Week, etc. The other day I was working and the frog croaked (my equivalent to “You’ve got mail”), but when I glanced at my secondary monitor where I keep mail and various toolbars, nothing showed up. That’s odd. But I wasn’t concentrating on incoming mail, so I just dismissed it. Then the same thing happened again. Still no new mail. This time I decided the incoming mail had been flagged as spam and shunted off into the junk mail folder before I got to see it. Never mind that this had never happened before. That was just a quick superstitious conclusion based on nothing more serious than the fact that I was working on something else and didn’t want to be bothered.
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Error-Prone Features, Incorporated

My last decision theory column featured a challenge to find common English words that have two meanings – each the opposite of the other. From the perspective of minimizing the errors in transmission, one would not expect symbols to be able to stand for different meanings, particularly not opposite meanings, but we seem to glory in skirting the edges of incomprehensibility in our common speech. As an example, consider the words “bad” and cool.” In common usage, these can assume contradictory meanings.

The word “dust” used as a verb can mean to remove dust as in cleaning, or it can mean putting dust on something as in gathering fingerprints.
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We All Make The Compromises That Work For Us

User groups, particularly ones catering to seniors, can generate interesting exchanges and be useful in many ways to someone who wants to tutor seniors. I frequent a local group, both to participate, and to listen. Sometimes by listening to seniors present problems they have been working on and then watching how the response goes, I can learn more about ways to talk effectively to the people I tutor. Tutoring without understanding the various ways that people can be confused is not very efficient.

Another benefit of listening to a peer group work out difficulties is that a tutor can get a better idea of what topics are of interest. Things that interest a person coming up to speed are often quite different from things that interest a person who is fluent in computer usage.
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A Standstill By Failed Distinction

This week has been relatively slow in terms of new events involving seniors becoming computer literate. However, I have been surprised by some questions raised by not-quite-senior users of the type that I normally assume are confidant when sitting in front of their monitors. There is not doubt that tutoring seniors is different than tutoring teenagers in computer literacy. In the first place, the teenagers are likely to show the tutor new shortcuts and features. But the boundary line between these two populations is certainly fuzzy and prone to error.

The first issue I ran into this week was showing a partially edited video clip on my neighbor’s computer. Since the clip was short, I copied it to a jumpdrive (thumbdrive?), and told him to plug it into a handy USB port to see what I had done. After some confusing interchanges, I finally came to understand that my friend did not understand the difference between a video in DVD format and any of the standard digital forms. And once he did understand that they are different (he used the example of DOC files vs PDF), he was not convinced that Windows Media Player could recognize the AVI file I gave him.
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Try To Enjoy

Sometimes I do feel like giving up. A few weeks ago my column featured a discussion of how to respond to a senior client who complains that when writing a letter, the computer behaves differently. Trying to correct a sentence results in overwriting the existing part rather than inserting new text. My struggle about how to explain the difference between “Insert” mode and “Typeover” mode attracted many helpful comments from readers which ranged from brute force ripping the “Ins” key of the keyboard to several software apps which make it more difficult to accidentally hit any of the common commands such as “Caps Lock” and, of course, “Ins.”

That’s all very nice, but today I got a phone call from the same client. “Remember the problem I had about not being able to put new text in a letter?” I waited with some trepidation.
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Surfing The Power Curve

Maybe my clients are actually becoming more computer literate or I’m getting behind the power curve myself. One of them recently bragged to me that she had finally got over her fears and actually bought something on eBay! She even signed up for PayPal and got verified. This might not be worth mentioning if she had done it as part of an assignment or program. In this case, however, she did it on her own as an intrepid explorer leaving the safe shores of email to risk fraud, identity theft, and getting on a hundred more spam lists. It took her a couple of false starts (her report – I wasn’t there) but she did it and was pleased with both the price and interaction with the seller. This is a success story. A small success by many standards, but you take the wins where you find them.
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Hamming It Up

In the last few columns, we’ve been discussing the statistics, probability, and decision theory as applied to communications. That is obviously a huge topic that cannot be adequately covered in this medium. I only hope to pique some readers’ curiosity enough to pursue further investigations on their own.

In particular, last time I mentioned at the end that messages can be encoded in such a way that they not only signal when an error occurs (as in parity checking), but they can also correct for errors. To convince skeptics that this can be done, first consider a very inefficient, but workable, error correction scheme. Simple send the desired message twice. If the two versions do not agree exactly, send a third version. Perform a majority rules vote sequentially on each bit (byte, or whatever). The result will be the correct version some of the time. Why some of the time? Why not all of the time? Consider two limiting cases: (1) perfect transmission, and (2) extremely noisy transmission. In case 1, the two copies agree and you have the correct message. In case two, there is no correlation between the three copies because they have all been so severely degraded. The algorithm fails to improve. (An alternate algorithm of simply sequentially averaging the bits probably will improve the situation if the noise is random and certain other conditions prevail.) Now imagine a knob to introduce noise into a message going from zero to overwhelming. As we increase the noise input from zero, this algorithm works perfectly at first and we always get the correct message up to some value on our noise knob. A higher values, the algorithm cannot remove all the noise.
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De-Mystification Of The Formidable

There’s a lesson in here somewhere, but I don’t know quite what to make of it. One of my senior clients recently purchased a new P4 laptop to replace his older 1 gig P3. The old one would have been good enough for his use, but two of the keys stopped working and rather than mess around with it, he just bought a new one without consulting me. That’s okay. I might have had some suggestions, but the client is always right. Anyway, he knows I fix up old machines and try to place them with kids who need them, so he offered to give me his old laptop, assuming I could fix it.

So far, so good. But here is the interesting part. My client was out walking in his neighborhood and passed a place where the residents leave old things that others might want. He noticed a laptop setting on the pile of discards, and it was a model like his broken one. The discard had no battery, but the charger was with it, and it looked in good shape so he bagged it. This is a man who has never looked inside a computer in his life. He has never opened a tower, and has never even added RAM. His computer skills are strictly limited to e-mail. His mechanical skills in repairing automobiles are excellent, but can that transfer to computer repair?
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