A hypothesis is an educated guess about what will happen in your experiment. It is NOT just a random guess! Your hypothesis should have some reason or factual basis for happening.

A good hypothesis almost always follows this pattern:

• It is brief
• It answers the "Question"
• It uses the same word pattern as the "Question"
• It is worded so that it can be tested
• It identifies the main variable
• It includes a reason for your guess

Let's go back to our example "Question" - Does temperature affect the flash rate of lightning bugs?

Here are some BAD examples of a hypothesis:

• Yes (That's it? That's all you got? It is brief, and it does answer the question, but it doesn't satisfy any of the other requirements.)
• Yes. Temperature affects the flash rate of lightning bugs. (This is slightly better. It satisfies most of the requirements. But how does it affect the flash rate and why do think your prediction is true.)

Here is an example of a GOOD hypothesis:

• An increase in temperature will cause an increase in a lightning bug's flash rate. I believe this to be true because I notice lightning bugs more on hot summer evenings.

This is a little long and wordy, but it makes a guess on how a temperature change will affect a lightning bug (it will increase its flashing), and it also explains why you made the prediction (you see them on hot evenings). This hypothesis is based on a natural observation, it is not just a random guess.

You might follow this general pattern when writing your hypothesis.... just fill-in the blah, blah, blah blanks.......

The blah, blah, blah will cause the blah, blah, blah to blah, blah because blah, blah, blah.