36 What order to apply Causal Map filters?

36.1 Keeping it simple

Itโ€™s easy to end up with complicated filters. It can get hard to explain to someone else (or even understand yourself) what is going on. Ideally you should have a clear model of what you are doing and be fairly consistent about it, and be able to explain and defend it. There is no difference on this point between qualitative and quantitative analyses.

36.2 Where do these islands come from?

Itโ€™s a really frequent problem that you do either a path tracing or a โ€œfind factors containing blah and two steps down etcโ€ and then โ€œselect โ€ฆโ€ to reduce number of factors or links, and then you get islands of stuff which donโ€™t seem to be related.

If you ensure that your select filters come earlier, you never get these islands and the resulting map makes sense as a product of the find or trace filter which you did.

This might seem a bit back to front, because in your working steps you usually apply a Find and then try to simplify it. It is also a bit strange in the sense that the numbers on the Select filter arenโ€™t as easy to guess. But it works.

In the same vein, it often makes sense to put any โ€œfind linksโ€ or โ€œfind statementsโ€ filters, e.g.ย looking for a particular village, right at the start.

Causal Map in any case enforces an ordering of the filters:

  1. Analysis filters (each of these can appear more than once)

  2. Conditional formatting filters (each of these can only appear once)

  3. Simple filters (each of these can only appear once)