Again, in a good experiment we:
* Identify all the variables. * Hold all the variables still (constant), * Adjust one variable and observe. * Draw a conclusion from the results. * Repeat the experiment adjusting other variables if necessary to clarify the conclusion. |
Frank wanted to test the traditional atlatl for throwing a spear at
seals.
He knew that the traditional length of atlatl is from his elboe to
his fist.
He tried an atlatl that was the traditional length, another that was
2" short and another that was 2" long.
He used the same spear in all his tests.
His variables were:
He later went on to test different spears, and used the same atlatl.
Another example:
Betty wanted to find out what kind of food camp-robbers (greyjays) liked. She put out a plate of saltine crackers, peanut butter and dry fish.
She put it out for the same length of time every
day.
She put the same amount of crackers, peanut butter
and dry fish on the plate.
She put the plate in the same location each day.
She recorded her data and entered the fair.
Another example:
Frozen tongue.
A boy wanted to find out why your tongue sticks
to the flagpole when it is cold.
He did an experiment. He did not use his
tongue, but a piece of cloth, sometimes dry, sometimes wet to imitate his
tongue.
He tested different materials under different
temperature conditions.
He recorded when the cloth stuck to the flagpole:
Dry above 32 | Dry below 32 | Wet above 32 | Wet below 32 | |
Wood |
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Plastic |
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Porcelain cup |
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Steel |
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