Fair Testing

We are conducting a fair test. To start a fair test, we need a question we want to investigate.

We have a lot of worm farms around our school. We all try and send our food scraps to the compost pile and the worm farms, instead of the landfill. Some schools sell the worm tea that collects at the bottom of their worm farms. It should be good for the environment, right?

Our question is, "does worm tea actually work?"

To make it a fair investigation we need to only change one variable. So...

• we are going to use the same sized containers with one pinhole punched in the bottom
• the soil used will come from the same place
• the containers will be placed beside each other on the windowsill
• 4 bean seeds will go in each container
• each group will select the four most strongest looking seeds
• all the seeds are planted 1 cm deep
• we will measure 20 mls of liquid for each container at a time

The only variable we will change is that one group will water their seeds with H2O, and the other groups will water their seed with worm tea.

We collected some soil from where the workers were constructing our new library.
We planted our 4 seeds in each container.
We measured 20 mls of either H2O or worm tea.