Thursday, November 15, 2012

When is Video Better?

Ok, I’m stuck, and I need your help.

At my company, we sell software tools that help Oracle application developers and database administrators see exactly where their code spends their users’ time. I want to publish better information at our web page that will allow people who are interested to learn more about our software, and that will allow people who don’t even realize we exist to discover what we have. My theory is that the more people who understand exactly what we have, the more customers we’ll get, and we have some evidence that bears that out.

I’ve gotten so much help from YouTube in various of my endeavors that I’ve formed the grand idea in my head:
We need more videos showing our products.
The first one I made is the 1:13 video on YouTube called “Method R Tools v3.0: Getting Started.” I’m interested to see how effective it is. I think this content is perfect for the video format because the whole point is to show you how easy it is to get going. Saying it’s easy just isn’t near as fun or convincing as showing it’s easy.

The next thing I need to share with people is a great demonstration that Jeff Holt has helped me pull together, which shows off all the tools in our suite, how they interact and solve an interesting and important common problem. But this one can’t be a 1-minute video; it’s a story that will take a lot longer to tell than that. It’s probably a 10- to 15-minute story, if I had to guess.

Here’s where I’m stuck. Should I make a video? Or write up a blog post for it? The reason this is a difficult question is that making a video costs me about 4 hours per minute of output I can create. That will get better over time, as I practice and accumulate experience. But right now, videos cost me a lot of time. On the other hand, I can whip together a blog post with plenty of detail in a fraction of the time.

Where I need your help is to figure out how much benefit there is, really, to creating a video instead of just a write-up. Some things I have to consider:
  • Would a 15-minute video capture the attention of people who Do people glaze over (TL;DR) on longish printed case studies on which they’d gladly watch about 15 minutes of video?
  • Or do people just pass on the prospect of watching a 15-minute case study about a problem they might not even realize they have yet? I ask this, because I find myself not clicking on any video that I know will take longer than a minute or two, unless I believe it’s going to help me solve a difficult problem that I know I have right now.
So, if you don’t mind giving me a hand, I’ve created a survey at SurveyMonkey that asks just three simple questions that will help me determine which direction to go next. I’m eager to see what you say.

Thank you for your time.

Tuesday, August 28, 2012

Is “Can’t” Really the Word You Want?

My friend Chester (Chet Justice in real life; oraclenerd when he puts his cape on) tweeted this yesterday:
can’t lives on won’t street - i’m sure my son will hate me when he’s older for saying that all the time.

I like it. It reminds me of an article that I drafted a few months ago but hadn’t posted yet. Here it is...

When I ask for help sometimes, I find myself writing a sentence that ends with, “…but I can’t figure it out.” I try to catch myself when I do that, because can’t is not the correct word.

Here’s what can’t means. Imagine a line representing time, with the middle marking where you are at some “right now” instant in time. The leftward direction represents the past, and the rightward direction represents the future.


Can’t means that I am incapable of doing something at every point along this timeline: past, present, and future.


Now, of course, can’t is different from mustn’t—“must not”which means that you’re not supposed to try to do something, presumably because it’s bad for you. So I’m not talking about the can/may distinction that grammarians bring to your attention when you say, “Can I have a candy bar?” and then they say, “I don’t know, can you?” And then you have to say, “Ok, may I have a candy bar” to actually have candy bar. I digress.

Back to the timeline. There are other words you can use to describe specific parts of that timeline, and here is where it becomes more apparent that can’t is often just not the right word:
  • Didn’t, a contraction of “did not.” It means that you did not do something in the past. It doesn’t necessarily mean you couldn’t have, or that you were incapable of doing it; it’s just a simple statement of fact that you, in fact, did not.
  • Aren’t, a contraction of “are not.” It means that you are in fact not doing something right now. This is different from “don’t,” which often is used to state an intention about the future, too, as in “I don’t smoke,” or “I do not like them, Sam-I-am.”
  • Won’t, a contraction of “will not.” It means that you will not do something in the future. It doesn’t necessarily mean you couldn’t, or that you are going to be incapable of doing it; it’s just a simple statement of intention that you, right now, don’t plan to. That’s the funny thing about your future. Sometimes you decide to change your plans. That’s ok, but it means that sometimes when you say won’t, you’re going to be wrong.
Here’s how it all looks on the timeline:


So, when I ask for help and I almost say, “I can’t figure it out,” the truth is really only that “I didn’t figure it out.”

“...Yet.”

...Because, you see, I do not have complete knowledge about the future, so it is not correct for me to say that I will never figure it out. Maybe I will. However, I do have complete knowledge of the past (this one aspect of the past, anyway), and so it is correct to speak about that by saying that I didn’t figure it out, or that I haven’t figured it out.

Does it seem like I’m going through a lot of bother making such detailed distinctions about such simple words? It matters, though. The people around you are affected by what you say and write. Furthermore, you are affected by the the stuff you say and write. Not only do our thoughts affect our words, our words affect our thoughts. The way you say and write stuff changes how you think about stuff. So if you aspire to tell the truth (is that still a thing?), or if you just want to know more about the truth, then it’s important to get your words right.

Now, back to the timeline. Just because you haven’t done something doesn’t mean you can’t, which means that you never will. Can’t is an as-if-factual statement about your future. Careless use of the word can’t can hurt people when you say it about them. It can hurt you when you think it about yourself.

Listen for it; you’ll hear it all the time:
  • “Why can’t you sit still?!” If you ask the question more accurately, it kind of answers itself: “Why haven’t you sat still for the past hour and a half?” Well, dad, maybe it’s because I’m bored and, oh, maybe it’s because I’m five! Asking why you haven’t been sitting still reminds me that perhaps there’s something I can do to make it easier for both of us to work through the next five minutes, and that maybe asking you to sit still for the next whole hour is asking too much.
  • “You can’t run that fast.” Prove it. Just because you haven’t doesn’t mean you never will. Before 1954, people used to say you can’t run a four-minute mile, that nobody can. Today, over a thousand people have done it. Can you become the most commercially successful and critically acclaimed act in history of popular music if you can’t read music? Well, apparently you can: that’s what the Beatles did. I’m probably not going to, but understanding that it’s not impossible is more life-enriching than believing I can’t.
  • “You can’t be trusted.” Rough waters here, mate. If you’ve behaved in such a manner that someone would say this about you, then you’ve got a lot of work in front of you. But no. No matter what, so far, all you’ve demonstrated is that you have been untrustworthy in the past. A true statement about your past is not necessarily a true statement about your future. It’s all about the choices you make from this moment onward.
Lots of parents and teachers don’t like can’t for its de-motivational qualities. I agree: when you think you can’t, you most likely won’t, because you won’t even try. It’s Chet’s “WONT STREET”.

When you think clearly about its technical meaning, you can also see that it’s also a word that’s often just not true. I hate being wrong. So I try not to use the word can’t very often.

Thursday, June 7, 2012

An Organizational Constraint that Diminishes Software Quality

One of the biggest problems in software performance today occurs when the people who write software are different from the people who are required to solve the performance problems that their software causes. It works like this:
  1. Architects design a system and pass the specification off to the developers.
  2. The developers implement the specs the architects gave them, while the architects move on to design another system.
  3. When the developers are “done” with their phase, they pass the code off to the production operations team. The operators run the system the developers gave them, while the developers move on to write another system.
The process is an assembly line for software: architects specialize in architecture, developers specialize in development, and operators specialize in operating. It sounds like the principle of industrial efficiency taken to its logical conclusion in the software world.


In this waterfall project plan,
architects design systems they never see written,
and developers write systems they never see run.

Sound good? It sounds like how Henry Ford made a lot of money building cars... Isn’t that how they build roads and bridges? So why not?

With software, there’s a horrible problem with this approach. If you’ve ever had to manage a system that was built like this, you know exactly what it is.

The problem is the absence of a feedback loop between actually using the software and building it. It’s a feedback loop that people who design and build software need for their own professional development. Developers who never see their software run don’t learn enough about how to make their software run better. Likewise, architects who never see their systems run have the same problem, only it’s worse, because (1) their involvement is even more abstract, and (2) their feedback loops are even longer.

Who are the performance experts in most Oracle shops these days? Unfortunately, it’s most often the database administrators, not the database developers. It’s the people who operate a system who learn the most about the system’s design and implementation mistakes. That’s unfortunate, because the people who design and write a system have so much more influence over how a system performs than do the people who just operate it.

If you’re an architect or a developer who has never had to support your own software in production, then you’re probably making some of the same mistakes now that you were making five years ago, without even realizing they’re mistakes. On the other hand, if you’re a developer who has to maintain your own software while it’s being operated in production, you’re probably thinking about new ways to make your next software system easier to support.

So, why is software any different than automotive assembly, or roads and bridges? It’s because software design is a process of invention. Almost every time. When is the last time you ever built exactly the same software you built before? No matter how many libraries you’re able to reuse from previous projects, every system you design is different from any system you’ve ever built before. You don’t just stamp out the same stuff you did before.

Software is funny that way, because the cost of copying and distributing it is vanishingly small. When you make great software that everyone in the world needs, you write it once and ship it at practically zero cost to everyone who needs it. Cars and bridges don’t work that way. Mass production and distribution of cars and bridges requires significantly more resources. The thousands of people involved in copying and distributing cars and bridges don’t have to know how to invent or refine cars or bridges to do great work. But with software, since copying and distributing it is so cheap, almost all that’s left is the invention process. And that requires feedback, just like inventing cars and bridges did.

Don’t organize your software project teams so that they’re denied access to this vital feedback loop.

Thursday, March 29, 2012

The String Puzzle

I gave my two boys an old puzzle to solve yesterday. I told them that I’d give them each $10 if they could solve it for me. It’s one of the ways we do the “allowance” thing around the house sometimes.

Here’s the puzzle. A piece of string is stretched tightly around the Earth along its equator. Imagine that this string along the equator forms a perfect circle, and imagine that to reach around that perfect circle, the string has to be exactly 25,000 miles long. Now imagine that you wanted to suspend this string 4 inches above the surface of the Earth, all the way around it. How much longer would the string have to be do do this?


Before you read any further, guess the answer. How much longer would the string have to be? A few inches? Several miles? What do you think?

Now, my older son Alex was more interested in the problem than I thought he would be. He knows the formula for computing the circumference of a circle as a function of its diameter, and he knew that raising the string 4 inches above the surface constituted a diameter change. So the kernel of a solution had begun to formulate in his head. And he had a calculator handy, which he loves to use.

We were at Chipotle for dinner. The rest of the family went in to order, and Alex waited in the truck to solve the problem “where he could have some peace and quiet.” He came into the restaurant in time to order, and he gave me a number that he had cooked up on his calculator in the truck. I had no idea whether it was correct or not (I haven’t worked the problem in many years), so I told him to explain to me how he got it.

When he explained to me what he had done, he pretty quickly discovered that he had made a unit conversion error. He had manipulated the ‘25,000’ and the ‘4’ as if they had been expressed in the same units, so his answer was wrong, but it sounded like conceptually he got what he needed to do to solve the problem. So I had him write it down. On a napkin, of course:


The first thing he did was draw a sphere (top center) and tell me that the diameter of this sphere is 25,000 miles divided by 3.14 (the approximation of π that they use at school). He started dividing that out on his calculator when I pulled the “Whoa, wait” thing where I asked him why he was dividing those two quantities, which caused him, grudgingly, to write out that C = 25,000 mi, that C = πd, and that therefore d = C/π. So I let him figure out that d ≈ 7,961 mi. There’s loss of precision there, because of the 3.14 approximation, and because there are lots of digits to the right of the decimal point after ‘7961’, but more about that later.

I told him to call the length of the original string C (for circumference) and to call the 4-inch suspension distance of the string h (for height), and then write me the formula for the length of the 4-inch high string, without worrying about any unit conversion issues. He got the formula pretty close on the first shot. He added 4 inches to the diameter of the circle instead of adding 4 inches to the radius (you can see the ‘4’ scratched out and replaced with an ‘8’ in the “8 in/63360 in” expression in the middle of the napkin. Where did the ‘63360’ come from, I asked? He explained that this is the number of inches in a mile (5,280 × 12). Good.

But I asked him to hold off on the unit conversion stuff until the very end. He wrote the correct formula for the length of the new string, which is [(C/π) + 2h]·π (bottom left). Then I let him run the formula out on his calculator. It came out to something bigger than exactly 25,000; I didn’t even look at what he got. This number he had produced minus 25,000 would be the answer we were looking for, but I knew there would be at least two problems with getting the answer this way:
  • The value of π is approximately 3.14, but it’s not exactly 3.14.
  • Whenever he had to transfer a precise number from one calculation to the next, I knew Alex was either rounding or truncating liberally.
So, I told him we were going to work this problem out completely symbolically, and only plug the numbers in at the very end. It turns out that doing the problem this way yields a very nice little surprise.

Here’s my half of the napkin:


I called the new string length cʹ and the old string length c. The answer to the puzzle is the value of cʹ − c.

The new circumference cʹ will be π times the new diameter, which is c/π + 2h, as Alex figured out. The second step distributes the π factor through the addition, resulting in cʹ − c = πc/π + 2πh − c. The πc/π term simplifies to just c, and it’s the final step where the magic happens: cʹ − c = c + 2πhc reduces simply to cʹ − c = 2πh. The difference between the new string length and the old one is 2πh, which in our case (where h = 4 inches) is roughly 25.133 inches.

So, problem solved. The string will have to be about 25.133 inches longer if we want to suspend it 4 inches above the surface.

Notice how simple the solution is: the only error we have to worry about is how precisely we want to represent π in our calculation.

Here’s the even cooler part, though: there is no ‘c’ in the formula for the answer. Did you notice that? What does that mean?

It means that the original circumference doesn’t matter. It means that if we have a string around the Moon that we want to raise 4 inches off the surface, we just need another 25.133 inches. How about a string stretched around Jupiter? just 25.133 more inches. Betelgeuse, a star whose diameter is about the same size as Jupiter’s orbit? Just 25.133 more inches. The whole solar system? Just 25.133 more inches. The entire Milky Way galaxy? Just 25.133 more inches. A golf ball? Again, 25.133 more inches. A single electron? Still 25.133 inches.

This is the kind of insight that solving a problem symbolically provides. A numerical solution tends to answer a question and halt the conversation. A symbolic formula answers our question and invites us to ask more.

The calculator answer is just a fish (pardon the analogy, but a potentially tainted fish at that). The symbolic answer is a fishing pole with a stock pond.

So, did I pay Alex for his answer? No. Giving two or three different answers doesn’t close the deal, even if one of the answers is correct. He doesn’t get paid for blurting out possible answers. He doesn’t even get paid for answering the question correctly; he gets paid for convincing me that he has created a correct answer. In the professional world, that is the key: the convincing.

Imagine that a consultant or a salesman told you that you needed to execute a $250,000 procedure to make your computer application run faster. Would you do it? Under what circumstances? If you just trusted him and did it, but it didn’t do what you had hoped, would you ever trust him again? I would argue that you shouldn’t trust an answer without a compelling rationale, and that the recommender’s reputation alone is not a compelling rationale.

The deal is, whenever Alex can show me the right answer and convince me that he’s done the problem correctly, that’s when I’ll give him the $10. I’m guessing it’ll happen within the next three days or so. The interesting bet is going to be whether his little brother beats him to it.