If you are talking about the Scientific Method than I hope this will answer your question.
- Ask a question
- Do background research
- Construct a hypothesis
- Test your hypothesis by doing an experiment
- Analyze your data and draw a conclusion
- Communicate your results
It is important when doing an experiment you pick one variable to modify over the course of the experiment and keep all other variables the same. For example if you want to see how light affects a pea plant, change the amount of light it receives but not the amount of water.