If more than half of Shakespeare's texts survive in more than one version, and an increasing number of his texts appear to have been co-authored with other playwrights, how do we define what constitutes a 'Shakespearean text'? Recent studies have proposed answers to this crucial question by investigating 'memorial reconstruction' and co-authorship, yet significantly they have not yet considered properly the many formal and stylistic synergies, interchanges and reciprocities between oral/memorial and authorial composition, and the extent to which these factors are traceable in the surviving playtexts of the period. It is precisely these synergies that this book investigates, making this site of interaction between actorly and authorial input its primary focus. Petersen proposes new quantitative methodologies for approaching form and style in Shakespearean texts. The book's main case studies are Hamlet, Romeo and Juliet and Titus Andronicus - plays drawn from the middle of Shakespeare's working career.