A parliamentary committee consists of a group of Members or Senators (or both in the case of joint committees) appointed by one or both Houses of Parliament. The purpose of parliamentary committees is to perform functions which the houses themselves are not well fitted to perform, such as carrying out inquiries, hearing witnesses, sifting evidence, discussing matters in detail and formulating reasoned conclusions. This kind of work is more effectively carried out by small groups of Members and/or Senators. A further advantage of committees is that several of them can operate at the one time, which enables many more matters to be dealt with. Committees, by concentrating on specific tasks or subjects, also offer the benefits of specialisation.