Is there any available figure of merit (FOM) table to understand whether element or compund that i found in my XRD analysis result is meaningfull or not?

I mean, "I would like to know if my FOM is 0.50, what does it mean, if it is 0.75 or if it is 0.25 what does it mean" How can i decide whether my FOM value is good enough to represent my compund or element obtained from XRD.