By the by, a word of caution, the person doing the analysis could also be limited by his/her own tendencies.
For example, if I didn't know some things regarding violins, I could think them often being "dusty" and "greasy" is a sign of poor cleaning habits and would start my analysis from there, when instead this "dust" and "grease" is a single thing, a resin used in the bow to improve the friction with the violin's own cords, and by extension, improving the sounds themselves. And this resin comes off as you play the instrument. Sure, a bit of cleaning, or lack thereof, may be at play, but in the first line of thought, I'd already expect it to be the whole issue since the beginning.