How to Appease the Demo Gods

When you are planning a demo, you must appease the Demo Gods, or their wrath will surely strike you down, making you appear to be a total fool in front of your professor, your fellow students, your boss, your co-workers, or even the people you were hoping might become your customers.

The following time-honored rituals are unsurpassed in their power to appease the Demo Gods, and perhaps even to make them smile upon you:

Freeze your code at least three to four days before the demo. The "simple" changes made at the last minute will invariably cause the Demo Gods to smite your software, rendering it totally useless at the most inopportune moment.
Never exercise any capability in your demo that you have not thoroughly tested beforehand. If you have not tested it, it does not work, no matter how careful and clever you thought you were, and no matter how simple the code seemed at the time.
Test your code early in the project on the platform that is to be used in the demo. My lab partner and I failed to perform this sacred ritual in our Winter 2000 CSE509 project presentation. Sure enough, an unexpected incompatibility caused our project to fail. We did avert the wrath of the Demo Gods, but only by hauling my desktop PC into the classroom at the last minute.
Rehearse your demo as if you were rehearsing a play:
1. Time each portion of your presentation.
2. Brutally cut anything that causes you to run overtime. After all, if it is really all that interesting, the audience will ask you questions about it anyway.
3. Allow no less than three minutes for every slide in your presentation.
4. Allow at least five minutes for questions.
5. Anticipate some questions, and prepare backup slides for these questions. Do not present these slides except in response to a question that specifically touches on the corresponding area. To figure out which questions are likely to be asked, rehearse in front of a friendly audience.
Have backup hardware available. Rehearse setting it up, and time how long it takes you to set it up. Rehearse one team member doing part of the presentation while another is setting the replacement hardware up.
Bring backup copies of your slides, for otherwise your laptop will be certain to fail to work with the projector. A USB memory stick works very well for storing backup copies, and, speaking as someone who has lugged tens of pounds of acetate foils through all 24 timezones and four countries in a one-week period, I can assure you that USB memory sticks are a very welcome development! Another good backup approach is to place a copy of your presentation on the web.
Arrive early enough to set up and check out any equipment that you need for your demo.
KISS: "Keep It Simple, Stupid!". The Demo Gods are less apt to wreak havoc with simple things.
If you have not already done so, join your local Toastmasters club and work toward your CTM.

What The Heck Are Demo Gods, Anyway?

A friend of mine runs his own business writing specialty software. He sells this software at trade shows, where he must do many demos. His wife could never understand why he was so paranoid about these demos: he would run through them multiple times, bring duplicates of all the required hardware and software, etc., etc. This took a lot of time and money that she naturally felt might be put to better use.

My friend tried to explain Murphy's Law to his wife, but she just didn't buy it. After all, why would perfectly good hardware and software just suddenly fail for no reason? And if you expected the hardware to fail, why not just buy good hardware?

After much contention over his obsessive preparations, my friend eventually came up with the concept of the Demo Gods. This deification of Murphy's Law seemed to satisfy his wife (though she still seemed skeptical at times), and for the most part restored domestic tranquillity.

And his wife is not alone. I have found that many people can relate to angry Demo Gods much more readily than they can to an abstract "Murphy's Law". If it works, go with it!