Hello everyone!

I'm looking for some clarification on when to use of, from, or about in combination with "draw a conclusion"

Some random google hits:
- "This is the way to draw a conclusion of something that happened in the past"
- "These banks enable us also to draw a conclusion of another nature"
- "From this we can draw a conclusion of some importance for the analysis of social justice"
- "In order to be able to draw a conclusion of the experiments on the expression of the z, y and i factors, it is necessary to find conditions where the merozygotes, ..." → shouldn't it be "from"?
- "How to draw a conclusion about an hypothesis if one study ..."
- "Why can't you draw a conclusion about the effect of one variable in an experiment when the others are not controlled"
- "What possible relevance can statements about the sample be in helping us draw a conclusion about the population?"

My thoughts so far:
- (to) draw a conclusion FROM facts/observations/experiments/experiences
- (to) draw a conclusion OF importance/another nature → so the 'of' "belongs" to the following part and not to the "draw a conclusion" part?
- (to) draw a conclusion ABOUT a certain topic (but from observations)

The differentiation between "of" and "from" doesn't always seem very strict, but using them interchangeably doesn't feel right, either.
Is it ok to use either one in formal or informal speech? Or is that ungrammatical?