I think being technically correct is not something you should aim for. Underexposure or Overexposure to a certain degree is all up to the photographer making the picture. If it looks good to you, then it is good. If you want to read some materials, the only book I would suggest is
Originally Posted by h501c
It is very important to be good at looking and getting the metering you want on a slide film. On print, you are pretty safe within a 1/2 stop margin. When taking things onto street, where I have to take shots fast and don't have time to setup and check exposure every time, I do a very simple trick; I just check that the highlights are not over 2-stops from metered (i.e if you want to capture some details in those highlights).