Experimental sciences are the systematic observations of phenomena for the purpose of learning new facts or testing the application of theories to known facts [1913 Webster] this means that experimental science is experiments and observations we make in order to learn new facts or testing the existing facts.
An experiment is method or investigation for testing your idea. For example experimenting on a new drug to fight diseases or Thomas Edison's invention of electricity and light bulb. These are some examples of an experiment. One can also say that any proven science theory has been experimented.
An experiment can be undertaken in many subjects other than all the science subjects for example Business and Management, Arts of fashion designing.
Talking about Business in day to day managers of the organization or the company take some new steps to implement new ideas without having any evidence to back them up. They make different offerings, try to distribute different things with different approaches, and they keep changing the way the work has to get done. These are all their ideas they are applying or you can say experimenting in different methods and they are observing the way in which they will get the best result. It’s likely that the resulting guesses will be wrong and, worst of all that very little will have been learned in the process but according to me this will be called an experiment because the managers has applied different methods to apply all his idea for a better sale.
For Visual art as an example artist try different types of medium for different artworks and they apply all the different ideas