How one compares and contrasts cases will depend on the purpose of the study and how cases were sampled. As discussed in Chapter 5, critical cases, extreme cases, typical cases, and heterogeneous cases serve different purposes. Other excellent resources for qualitative case analysis include Stake (1995), Marriam (1997,) Yin (1994), Hamel (1993), and the U.S. General Accounting office (1987). To pursue case studies as stories that build on and display the elements of good storytelling, see Glesne (1999).