Setting YARPP Threshold

I installed YARPP and found it to be delightful. The only thing is that it does not include posts that should be included and have not found a way to not display improper post choices. Searching the forums, it seems to be a threshold related thing, but I have not been able to figure out how to change it. I did install YARPP Experiments. Including posts in the same category did not get them included.

I’m not a programmer, so if I need to do any of that, I need explicit instructions.

Thank you!!