Source tracing is more conservative than path tracing and helps us avoid The transitivity trap.

• Avoid the "transitivity trap": if source 'A' says that sanitation influenced wellbeing, and source 'B' says that wellbeing influenced peace, you have to be careful in concluding that sanitation influenced peace.
• Source tracing eliminates this false conclusion by only tracing, link by link, stories told in their entirety by specific individuals. It is a safer, more conservative approach.
• This can be quite tricky to do: you need patience or specialised software like Causal Map!

If doing any kind of recoding, even zoom, and especially soft recoding, the order makes a difference. Doing the tracing first is more conservative.