I've got a good test for you, test the placebo affect. Give everyone a sugar pill and say it's a natural sleeping pill that will make them sleep better that you want to test the effects of. Tell them to take 2 at night before they go to bed.
Now the next day, talk to them again and ask them if it had made them sleep better, or if there were any side affects you had noticed.
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If your teacher will not let you do that one, then test the claims of astrologers..
To start off you will need some horoscopes;
For example, I just went to Yahoo! Astrology (
http://astrology.yahoo.com/astrology/ ) and got these:
Aries: It's a day for quick action. Opportunities will knock, but they won't stick around.
Leo: Today you'll meet someone who changes your opinion -- and you'll be happy about it.
Sagitarius: Doing things just for pleasure once in a while is a good idea. Explore it today.
Taurus: The shopping siren may be calling, but don't rush out to buy anything just yet.
Anyway you get the idea...
Now you present all of these to people (put a 1,2,3,4 on them for your own reference later on) and ask them to give it a rank from 1-10 about how accurate it was at the end of the day, and to state their star sign (a good idea would be to use the more extended horoscopes, as they have a greater chance of getting a hit).