Final answer:
One must have a hypothesis before designing and conducting experiments. A hypothesis is essential for guiding experimental design and is a key component of the scientific method. It does not determine the success or failure of the experiment; it is a starting point for testing and refining scientific predictions.
Step-by-step explanation:
Before designing and conducting experiments, one must have a hypothesis. A hypothesis is a proposed explanation made on the basis of limited evidence as a starting point for further investigation. It guides the direction of the experiment and is essential for the development of a scientific study. To design a controlled experiment, a hypothesis is crucial because it predicts an outcome that can be tested and potentially falsified through experimentation.
During the scientific process, if a hypothesis is rejected by the experiment, it does not necessarily mean that the experiment was a failure. Instead, it represents the normal functioning of the scientific method, with the hypothesis being refined or replaced. As hypotheses are tested and as evidence accumulates, they may develop into well-substantiated explanations known as theories, which can be supported by multiple experiments. The conception that a theory becomes a law over time is a misconception; theories and laws serve different purposes in science. A law describes what happens, while a theory explains why something happens.