hypothesis

A hypothesis is an assumption that may be true, but has not yet been tested by doing experiments and collecting data.

A hypothesis says what the researchers expect their research study will show. Hypotheses enable researchers to predict what could cause or influence something else.

For example:

Scientists do experiments in laboratories to see if their results support their hypotheses.

A long time ago, people thought that the earth was flat. Magellan sailed around the world to prove that this hypothesis was not true.