Keep the results a secret. Do the math without a calculator. Change all of the variables in the experiment. Ask other scientists to attempt to reproduce the results.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: What should a scientist do to help make sure the results of an experiment are unbiased?
Possibilities:
- Keep the results a secret.
- Do the math without a calculator.
- Change all of the variables in the experiment.
- Ask other scientists to attempt to reproduce the results.

Ask other scientists to attempt to reproduce the results.