Net good refers to the overall total benefit (or harm) a particular thing brings to society.
In practical usage this is almost always a rough estimate based on intuitive judgment of a number of factors; it is rarely possible to assign any kind of realistic numeric value to each choice so that they may be objectively compared. The best which can usually be done is to decide whether the net good is positive, thus making the outcome desirable or good, or negative, thus making the outcome undesirable or bad.
It is also reasonable to discuss the relative net good of each of several different possible choices, and to evaluate the intensity of goodness or badness in rough orders of magnitude ("somewhat good", "really very bad", and so on).
Analysis of the different methods by which such decisions are made is a relatively new field, but is evolving rapidly due to new technology (primarily the Internet and interactive web software) which makes experimentation with different methods much cheaper and quicker than it used to be.
- Dispute resolution technology is typically geared towards decisions involving smaller numbers of people, but includes some ideas which could be scaled up to a society-wide level.