Definition: CRC cards
(Class Responsibility Collaboration card) An object-oriented design method that uses ordinary 3x5 index cards. Developed by Ward Cunningham at Textronix, a card is made for each class containing responsibilities (knowledge and services) and collaborators (interactions with other objects). The cards provide an informal, intuitive way for group members to work on object design together.
For a book on CRC cards that provides a clear introduction to object concepts and modeling, read "Using CRC Cards" by Nancy Wilkinson, published by SIGS BOOKS, ISBN 1-884842-07-0.