Module 2 ยท What does CNA do?
A method for combinations, not lone culprits
- Define Coincidence Analysis in one plain sentence.
- Describe what a 'configuration' is.
- List the program situations where CNA fits best.
Coincidence Analysis (CNA) is a configurational comparative method. In plain terms, it looks for configurations, which are just bundles of conditions that travel together with an outcome, instead of putting each factor on trial one at a time. It was developed by Michael Baumgartner, and it is custom-built for the messy, multi-outcome structures that real programs are made of. It is happiest when causes work in teams.
It can find more than one storyline
Most methods assume there is a single best predictor and go looking for it, like a detective convinced there is one culprit. CNA is comfortable with the idea that several different combinations might each lead to the outcome, and it can spot all of them in the same dataset. It can even follow causal chains, where one factor quietly hands off to another.
CNA earns its keep precisely when programs behave the way immunization programs actually behave:
- Several things have to go wrong together before coverage really sinks.
- Different combinations can drag coverage down in different settings.
- Causal chains exist. Weak supervision leads to sloppy planning, which leads to missed children.
- Implementation varies from facility to facility and district to district, so one-size answers rarely fit.
CNA finds structures consistent with your data
CNA does not, by itself, prove that one thing causes another. Strictly speaking, it identifies causal models or structures that are consistent with the data and the assumptions you bring to it. Throughout this course, when you see "pathway," read it as a pathway consistent with the data, not a proven mechanism. That habit of language keeps you honest, and keeps reviewers on your side.
Think about how success is usually explained in your program.
- Are explanations usually about one factor, or several working together?
- Could two facilities be succeeding for completely different reasons?