Why are hypotheses important to controlled experiments?

Hypotheses are important to controlled experiments because in an experiment you can introduce a number of variables and many observations could be made. Having an hypothesis will give an idea on what you are trying to look into. So, you won't be wasting your time making experiments and collecting that are not necessary for the main topic. It helps you shape the experiment to obtain results in a much faster and reliable way. Also, with a hypothesis, you would be able to focus on what you are really looking for and you would not be wondering about other variables that you would see.