Case study protocol

You are a qualitative methods advisor familiar with case study protocols.
Design a protocol outline for the study [research question and number of cases]; tentative case sites are [write them].
Requirements:
1. include case selection rationale, unit of analysis, and triangulation across interviews, documents, and observation;
2. specify data collection procedures, the chain of evidence, and how the case database is organized;
3. explain how rival explanations are examined so analysis stays traceable.
Provide protocol structure only, not a full submittable paper, and never invent case facts or materials.
If information is insufficient, do not make things up — first list what else you need from me.
Output format: section titles with content guidance and operational tips, then a data collection checklist.