All the things you keep the same to keep the experiment fair are?

To keep an experiment fair, it is essential to control variables such as the environment (temperature, light, and humidity), the materials used (ensuring they are consistent and of the same quality), and the methods of measurement (using the same tools and techniques). Additionally, the same procedures should be followed for all trials, and the subjects or samples should be randomly assigned to different groups to eliminate bias. Maintaining these constants helps ensure that any observed effects are due to the independent variable being tested.