an experiment
Examples
Don't be too timid and squeamish about your actions. All life is an experiment.
To consult the statistician after an experiment is finished is often merely to ask him to conduct a post mortem examination. He can perhaps say what the experiment died of.
A theory is something nobody believes, except the person who made it. An experiment is something everybody believes, except the person who made it.
All life is an experiment. The more experiments you make the better.
Marriage is too interesting an experiment to be tried only once.
That, at any rate, is the theory of our Constitution. It is an experiment, as all life is an experiment.