When people say quality, what do they mean?

I look for a discussion that people stay on the topic with a number of reasons to support their view point. I don't rate any one sentence or one word posts, as they aren't quality posts to me. The person doesn't have to agree with me, as I have given many positives for not agreeing with me. I want people to convince me that I need to look at both sides of the issue fairly.

Those are all very good questions. I guess I always assumed it was the length, but then what is stopping people from going zzzzzzzzzzzzzzzzzzzzzzz for three lines? Maybe it is a combination of both?

For me quality post is not just by length it can be not to long. Quality response is write the real response, example I'm asking for money then if there is response speak nothing about money like "I don't know" I will not rate it.

Quality meaning dont start a stupid and lengthy discussion. The discussion must have a good content.