Usually, of course, the best support for claims comes from multiple pieces of data, and so the most persuasive arguments are often composed of a combination of qualitative and quantitative data.
I agree with this. To become truly informed about a subject you have to see it from all sides. It's like an old Buddhist story I read where a king brought a bunch of blind men and gave them an elephant. They went around feeling the elephant and each man claimed it was a different type of beast. They all were so convinced they were right that they started fighting among themselves. But the fact was that they were all wrong. But once they banned together with their thoughts and ideas they were able to fully piece together what it was they were feeling.