Which organization is NOT a professional association for librarians?

The American Union of Library Employees is not a professional association for librarians in the same way that the other choices are. While it represents the interests of workers in the library field, it primarily functions as a labor union focusing on the rights and working conditions of library employees rather than serving as a professional association aimed at advancing the profession of librarianship.

In contrast, the American Library Association, the Association of College and Research Libraries, and the Public Library Association are all professional organizations dedicated to supporting librarians through advocacy, professional development, and the promotion of library services. They provide resources, networking opportunities, and platforms for the exchange of ideas among those who work in various sectors of librarianship. Understanding the distinction between labor unions and professional associations is crucial in identifying the roles these organizations play in the library community.