Ask any patent attorney about patent quality and you will open a big discussion. Most of the time, you will hear the phrase “I know it when I see it”, or something to that effect.
There are some overt things that give a patent ‘high quality’. These things are things like good spelling, proper grammar, clear writing, and well done figures.
There are also the legally important aspects to writing a patent application, such as properly characterizing the invention, giving support for the claims, and good patent drafting skills.
Part of the intangible ‘thing’ about patent quality is whether or not the drafter appears to really understand the invention. With some patents, you can tell that the drafter was fishing around with no clear sense of direction and appears to be filling the page with words that somehow may relate to an invention. Other patents are clear, direct, and describe the invention in a way that you ‘know’ that they knew the technology.
But that really is not the most important part of patent quality.