Although Robertson's reputation as a revolutionary dramatist is debated, his importance in the development of modern stagecraft is generally agreed. Before him, star actors usually had control of scripts, and theatre managers had control of casting. Robertson insisted on retaining control over his scripts and casting and required that his actors follow his directions – a novel concept at that time. Dion Boucicault had been a forerunner, directing spectacular productions of his own plays, but Robertson applied the directorial precept to English domestic drama for the first time. Unlike Boucicault he did not act in his plays but applied himself exclusively to directing (or as it was called at the time "stage management") and in that capacity he could focus on ensemble and balance. Gilbert attended Robertson's rehearsals and later directed his own plays and operas based on what he had learned. He said of Robertson: