Restate, in brief terms, the purpose of your experiment and your hypothesis. Rework any questions into statement form. For example, do not write: "What is the effect of fertilizer on petunias?" Instead, write: "This experiment examined the effect of fertilizer on petunias."
State whether you accept or reject your original hypothesis, backing up your conclusion with your interpretation of the data. Use specific facts in your argument--for example, plants grown with the nitrogen fertilizer grew an average of three inches taller. If your results did not confirm your hypothesis, analyze possible reasons why results were different from what you expected.
Discuss limitations or errors in your experiment, such as limitations in the equipment, possible measurement errors or confounding variables. Describe the limitations as accurately as possible. For example, the quality of your local soil may have stunted the growth of all the plants, or uneven rainfall may have distorted your results.
Describe possible strategies for avoiding the experimental limitations analyzed in the previous paragraph. Make sure your recommendations are realistic. For example, you could grow your plants in a greenhouse to avoid erratic rainfall. In addition, note any further experiments that would clarify the meaning of your results.