Cases are stories about specific activities of a real world practice with a purpose to educate. Often providing contextual background information, cases present problem situations and expert solutions. Studying cases offers students the authentic learning experience of "seeing" how experts carry out design projects in the practice. In this paper, we present our ongoing work of designing case-based authentic learning activities in usability engineering (UE) courses, and developing collaborative tools to support the activities. We describe a collaborative case commenting tool that enables students to collaboratively browse and comment on the documents from an existing usability case library both synchronously and asynchronously, and a collaborative case builder tool that provides a virtual workspace for the students to collaboratively build a case based on their authentic design project. We discuss three collaborative case commenting activities in the UE course of Spring 2006, and a collaborative case building activity in the UE course of Fall 2006.