[Yin] Single Case or Multiple Case Study? -- Rethinking My Research Design

This semester I begin to dwell myself into the world of case study. Although someone suggested my that the best way to learn how to conduct a case study is "learning by doing," I believe I would be better to gain some basic ideas of how it works, especially now I'm far away from school and need to prepare everything by myself.

I started from two books, Merriam's and Yin's. Merriam was the first book I chose to read. It was a 1998 edition borrowed from one of my friend. I also purchased the 2009 edition, which is a slightly different from the previous version, but currently I sticked into the 1998 edition.

Merriam's book for me is easy to read. I think it is a good book for reviewing basic concepts for qualitative study methodology after I've finished CI8148, the foundation course of Qualitative Study. When I was reading Merriam's book, I felt like I was talking with an old friend. Everything is very familiar to me. This book, basically is a handbook for qualitative study in general, except for a couple sections that specially aim at case study. Yin's book is speaking a foreign language to me. I felt like I can kind of understand his ideas, however, I didn't master these ideas right now. The examples provided by Yin were also a little bit distanced from my comfort zone. I've read two chapters so far and not sure if I will finish the whole book. But I'm interested the data analysis portion written by Yin anyway. Merriam's book, in another side, sometimes is too "natural" for me. She defined the case study as a final product. The data collection and analysis process, in my own opinion, shares mostly the same concepts from other qualitative approaches. So I see these unfamiliarity and the uncomfortableness when I read Yin's book in a good way. It puzzles me but push me to think more.

I kept looking back to my mini proposal when I was reading Yin's book. One of the idea interest me is how Yin distinguishes single-case designs and multiple-case designs. He presents four different designs by following matrix:

[Grachic from Yin (2009) Case Study Research: Design and Methods. Fourth Edition. p.46]

"The matrix first shows that every type of design will include the desire to analyze contextual conditions in relation to the 'case,' with the dotted lines between the two signaling that the boundaries between the case and the context are not likely to be sharp. The matrix then shows that single- and multiple-case studies reflect different design situations and that, within these two variant, there also can be unitary or multiple units of analysis. The resulting four types of designs for case studies are (Type 1) single-case (holistic) designs, (Type 2) single-case (embedded) designs, (Type 3) multiple-case (holistic) designs, and (Type 4) multiple-case (embedded) designs" (p.46).

My design seems cannot be categorized into any of these designs above, instead, it looks like the following picture:

In my initial thoughts, to understand how K-12 teachers use iPad in their classrooms, I selected five teachers who teach five different subject matters in the same grade of a same school which begins its iPad initiative. My design is five different cases (teachers) in a single context (school). I'm not sure if it can be categorized as a "multiple-case study." It relates to my research question: do I want to find the similar pattern from these five cases, or find the differences between these five cases? 

Or this cannot be counted as a multiple-case study, instead, it should be a "Single-case embedded design" with multiple units of analysis (Type 2 design described by Yin)? However, if it is this kind of Type 2 design, the case become "the whole iPad initiative" of a school, which seems not match to my research questions.

The question can also be linked to the rationale of why I choose five different teachers with different subject matters in a school. Based on my original thoughts, I thought five different teachers can be "representative" (I am a little afraid to use this word after I take CI8148) and understand the phenomenon in a K-12 school. After I talked to one of my friends who conducted a case study before, I realized the design could be problematic. If I want to understand the "difference" of teachers' iPad use in different content areas, one teacher in a content area seems to be weak because I cannot find the "pattern" in each area and compare these different patterns among different teaching practices in different areas.

If I'm really interested in these differences among content areas and want to put it into the list of my research questions, the design needs to be changed because I don't think I can handle at lease 10 teachers in  five different areas. I came up with a possibility of another design: focus on two different areas, say, language art and science, and study 2-3 teachers in each area, find the patterns and compare. 

Of course this design could be easily changed when I actually begin to find my cases in the future. My ideas could change when I continue to read Yin's book as well. I'm not sure if my understandings are correct right now.