Comment by tokenadult | Hacker News Reader

Comment by tokenadult | Hacker News Reader

When hiring engineers for my company, I might ask, what are the trade-offs in using PowerPoint-style slides to make a technical presentation? And I would expect an astute engineer who has thought about technical communication to refer me to either serious

http://www.edwardtufte.com/bboard/q-and-a-fetch-msg?msg_id=0...

or humorous

http://norvig.com/Gettysburg/

discussions of the defects of PowerPoint slides as a communication tool.

The slides shown here cover some interesting ground, and I was glad to see the specific reference to Enrico Fermi, who popularized the kind of estimation question discussed here in certain circles. Certainly, it is beyond dispute that

"Although most engineers remember key numbers related to their field, no-one has every detail at their fingertips

"Hence we need to estimate not only the values of numbers we need, but which numbers are appropriate, and how to perform the calculation

"the emphasis here is on 'order of magnitude' estimates – to the nearest factor of 10

"it is also important to remember that these are rough estimates and to place only appropriate reliance on the results"

The last point is the most crucial. It is vital to remember how much uncertainty there is in your estimates, or overall in your model that includes both exactly measured and estimated values. The model is not reality. It is not easy to get engineers to remember that they have to look into the mechanism of the model to understand how it works. That's why a NASA Mars probe failed when one part of the engineering team used United States customary units while another used metric units to design modules of the probe that were supposed to communicate values to each other.

http://edition.cnn.com/TECH/space/9909/30/mars.metric.02/

What are the alternatives though? (to powerpoint)

I love chalk and talk but it puts a lot of load on the speaker. My Electricity and Magnetism professor basically pushed it to the limit I think. He had a carefully cultivated temper that was bad enough to keep 100 students totally silent for 50 minutes and he used about five different colors of chalk, but there are limits to what you can scrawl out on a blackboard.

You can distribute written documents, this gives you maximum opportunity to convey information, but you can't force people to actually read them. Going from a paper memo to email exacerbates this I think. Best case scenario, you can present very clear and well structured information but if you go past two pages you have to wonder if anyone is really paying that much attention. As a "best case example" I'd look at something like this memo that Robert McNamara wrote to LBJ about a month after LBJ took office: https://www.mtholyoke.edu/acad/intrel/pentagon3/doc156.htm . A benefit of written work is that you are committed to your words. But: creating a concise and readable written document that will effectively spread your thoughts is excruciatingly difficult. You can't write a book of background info every time you have a staff meeting.

...

About remembering that you have a rough model though, I think the key thing is that when you realize that there is something you are interested in measuring and once you have a model then you can start looking for quantities you can actually measure to (in)validate and tighten the model. Always be model checking.

I spent four years studying physics and mathematics, and I only had one professor that used transparent acetate sheets with notes pre-written and examples on them. All my other professors wrote out everything with chalk. Heck, we were excited when they used more than one colour of chalk, because that meant there was something exciting about to come up.

Additionally, having chalk & talk meant that many students showed up to class, instead of just relying on "reading" printouts of slides that the professor made available. I would venture a guess that I would have performed rather poorly in a class that had powerpoint slides, due to my inherent laziness in my early 20s.

Acetate rocks, especially when its well written and you can pop into the prof's office and have a tea and chat and do some photocopying. I learned much more this way.

Chalk, we spent more time dictating and deciphering the babbling fool who can't communicate it all concisely from memory.

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