This thread is for asking any questions that might seem obvious, tangential, silly or what-have-you. Don't be shy, everyone has holes in their knowledge, though the fewer and the smaller we can make them, the better.
Please be respectful of other people's admitting ignorance and don't mock them for it, as they're doing a noble thing.
To any future monthly posters of SQ threads, please remember to add the "stupid_questions" tag.
Suppose a research team works on the methods comparability issue. (Specifically, 'is it possible to compare the percent of fungal colonization [the length of roots occupied by fungus divided by the total length of the root system], obtained by using Technique A [staining with fuchsin] with the figure for Technique B […Trypan blue]? For further specifics, see Gange et al, 'A comparision of visualisation techniques for recording arbuscular mycorrhizal colonisation', although I promise it is not required for this SQ.)
The problem with both Techniques A and B is that different researchers' estimates may vary plus minus 10% (for the same slide). The team, aware of that, assigned just one, experienced member to the recording part, and I think doubled the sample (the number of viewed fields of vision per slide). They showed that the figures for A and B can be about 20% different.
If I have to guesstimate how my own results for a different set of roots of the same species of plant can be compared with somebody else's, and I use A and he uses B, do I have to allow for a possible 40% gap of total variation? Because that would make it a bloody useless comparison...
Suppose I do a similar methodology study myself, and I can ask a (even less experienced partner) to score all those fields of vision that I view myself, would our composite estimates for A and B be more, well, robust than if I did it alone? It seems so, but then again, maybe it is better if she scored different fields of vision on the same slide. I am confused.
For a stupid questions thread the language sounds remarkably domain-specific. Consider rephrasing in ELI5.