Step 3. Hypothesis

• Write down what you expect to happen before you try your experiment.
• Be specific! Make a chart of the numbers that you are predicting and give reasons for your guesses.

Include other guesses such as height, color, condition, size, time, etc.

Example:

I believe that the ivy plants closest to the fluorescent light will grow best. Fluorescent lights are often used in indoor gardening and do not emit harmful quantities of light. Based on my research, I think this group will grow 6 cm. taller during the experiment. Also, because these ivy plants get more light, their root systems will also grow best. The following is a chart of my predicted results for each group:

Hypothesis - Ivy Group A averages

 Date Height in cm. # of leaves Avg. root length in cm. Expected Observations 1/1/99 4 5 0 Initial sizes. 1/8/99 4.5 5 0 Leaves will grow before roots start. 1/15/99 5 5 1 Roots will begin to grow. 1/22/99 6 6 1 More leaves will follow. 1/29/99 7.5 6 2.5 Leaves and roots will grow faster. 2/5/99 8 7 3 All parts will grow fast. 2/12/99 9 7 4.5 Roots will grow very fast. 2/19/99 10 8 6 Plant is very healthy, ready to transplant. Totals 6 8 6

(You could also graph this hypothesis data)
Notice that this is just the chart for group A. You would also need hypothesis charts for groups B, C and D

• Your experiment should prove whether or not your hypothesis is true.

• It should be a controlled experiment. This means that each group should have everything the same (amount of water, # of leaves, etc.) except for one variable (in this case, distance from the light). Each experiment should have at least 3 trials , in this case, 3 plants each that are 5, 10, 15, and 20 cm. from the light). That way, you can determine an AVERAGE height for each group of plants.