What is considered a good signal strength?

I haven't been getting a signal for my services. There was construction going on right in front of my house and I suspected that they cut or nicked a line. I went round and round with technical support because they keep wanting to charge me $55 to send someone out when I suspect the problem is outside. We had a tech come by the house to check the outside only (to avoid the fee) and he said my signal was "good" never gave me a number. I saw another tech upgrading my neighbors service and he checked it again for me...he said it was at a "12" by the road and at a "-8" at the drop line. This tech said this number was NOT good and suggested I call back and get another drop line. He stated that it starting off at a -8 then that drop is hooked up to a 3 way splitter before coming in the house could be why I am not getting a signal.