Most productions begin the first day of rehearsals with a whole cast read-through of the play. A unit for early rehearsals might be a complete scene but could also be a section from a longer scene involving a core group of characters and stopping at the point other characters enter. The rehearsal period is not simple and linear, as all the inputs with collaborators permeate the process throughout. There are some Stanislavskian-type exercises that help some modern actors build character in the early rehearsal days. During rehearsal, actors define their characters from the interaction with other characters. The characters are not static in how they think, feel and act but are dynamic and changing according to circumstance. During rehearsals for every play by Shakespeare, there is the stimulating and crucial time needed to work on soliloquies; the importance of soliloquies for the actor is not to be underestimated.