Examining oral argument in the Australian High Court and comparing to the U.S. Supreme Court, this article shows that institutional design drives judicial interruptive behavior. Many of the same individual- and case-level factors predict oral argument behavior. Notably, despite orthodoxy of the High Court as “apolitical,” ideology strongly predicts interruptions, just as in the United States. Yet, important divergent institutional design features between the two apex courts translate into meaningful behavioral differences, with the greater power of the Chief Justice resulting in differences in interruptions. Finally, gender effects are lower and only identifiable with new methodological techniques we develop and apply.

In multi-panelled higher jurisdictions, a larger, extended formation of judges tends to be established within the court. It bears various names: the grand chamber, the extended chamber, the expanded composition, the reunion of several chambers, a court sitting en banc, an extended section or a division of a court. In larger but not too large jurisdictions, the same role is adopted by the plenary. For ease of reference, I shall refer to all such extended judicial formations with the generic name ‘grand chamber’.

To bear the same name does not necessarily mean to perform the same function. As a Czech lawyer, I have always intuitively assumed that the role of such a body within an apex court is to unify the case law. In the Czech Republic, as well as in a number of other supreme continental jurisdictions for that matter, there tends to be only one reason for the presence of a grand chamber within a supreme court: to unify the diverging lines of case law and to set a clear line of precedent. However, that has never really been the job description, least of all the practice, of the Grand Chamber of the Court of Justice of the European Union (‘Court’). This begs the question: what may then be other structural reasons for the existence of such a body within an apex jurisdiction? What is the specific role, function, and ensuing justification for the Grand Chamber of the Court?

This article offers some personal reflections on that question. It is structured as follows: it begins with a short comparative overview of some of the grand chambers within European (national) courts, overseas in the common law world, as well as at the European Court of Human Rights, in order to tease out the functional rationale for various types of extended judicial compositions within those systems (Part I). Next, two types of such functional justifications for grand chambers in the form of ideal models are identified (Part II). Finally, those justifications are then considered in light of the legislative design and the current practice of the Grand Chamber of the Court, before concluding with two modest suggestions (Part III).