To write a hypothesis, follow these steps:

1. Ask a clear, focused research question you want to answer.
2. Do preliminary research to learn what is already known about the topic.
3. Identify and define your variables: independent (what you change) and dependent (what you measure).
4. Formulate your hypothesis as a clear, concise statement predicting the relationship between variables.
5. Refine it to be specific and testable, including the relevant variables, study group, and predicted outcome.
6. Phrase your hypothesis in different ways, such as an "if... then..." statement or as a correlation or difference between groups.
7. Write a null hypothesis if doing statistical hypothesis testing, which states no effect or association between variables.

A hypothesis should be a testable, falsifiable prediction based on existing knowledge, not just a guess. For example, "If people over 60 consume an apple daily, then they will visit the doctor less frequently." This sets the independent variable (daily apple consumption) and dependent variable (doctor visits) clearly. This process ensures your hypothesis guides your research effectively and leads to measurable outcomes.