Here's why:
* Objectivity: Scientific writing aims for objectivity. Using personal pronouns can make the conclusion seem subjective or biased.
* Focus on the research: The conclusion should focus on the findings of the experiment, not the researcher's personal opinions or feelings.
* Formal tone: Science fair projects require a formal and professional tone. Using personal pronouns can make the conclusion sound less formal.
Instead of using pronouns, you can:
* Use passive voice: For example, "The results showed that..." instead of "I found that..."
* Refer to the experiment directly: "This experiment investigated..." instead of "We investigated..."
* Focus on the data: "The data collected indicated..." instead of "I observed that..."
Example:
Using pronouns: "I found that the plant grew taller when watered with fertilizer."
Without pronouns: "The results showed that the plant grew taller when watered with fertilizer."
Remember that the specific guidance for your science fair may vary, so it's always best to check the rules provided by your teacher or organizer.