When digging deep into research methodology and summaries, the water if very muddy indeed.
It is common place to hear the expression 'but research says...' and a specific piece of research may be quoted - and then this passed around from one person to another without people digging deep into any potential confusion, flaws, poor practice, poor reporting - and so on.
Heather F is a master at digging deep.
The EPPSE research is often quoted, so do read this please:
https://heatherfblog.wordpress.com/2015 ... ith-eppse/
No one questions what they want to believe. The problem with EPPSE