This term, I took a qualitative methods class where we talked a lot about post-modern ideas (Pretty unusual for a professional degree, right? Not at Berkeley!) Basically, post-modern thinkers deny that we can understand reality. To the post-modern purist, knowledge is nothing but a biased representation of a reality we can never know. The only useful occupation for a knowledge producer is to critique representations of knowledge, demonstrate who they really benefit, and empower marginalized people in the knowledge production process. This is done with qualitative research.

Maybe all knowledge is biased. What do I know? But in class I got really tired of the argument over bias. We need knowledge of the world to make progress, but at school we're caught between the post-modern critics who do not supply knowledge of reality, and the quantitative "scientists" who see universalities and rationality where there isn't any.

The more important debate is not between the post-moderns and the positivists, but between the positivists and the post-positivists, who argue over what methods can best describe reality. My instinct is that qualitative analysis has more uses than it's given credit for. But for qualitative methods to be useful, they must help us describe and analyze reality better than quantitative methods.

I argue that qualitative methods are a good way of describing the particular, as opposed to the universal. Quantitative analysis presuppose some degree of homogeneity. In order to count and aggregate data, you have to reduce reality to its homogeneous elements. Let's say you have you have two apples and two pears. They can only be added together at the most simplistic level of abstraction. They are all fruits, so you have four fruits. But in the process of reduction, you can lose essential facts about reality. They're no longer apples and pears- just fruits. Maybe you have two apples, but one grew in your backyard, and you planted the tree when you were a kid. The whole story of the apple is neglected in a quantitative analysis.

With human beings, the process of reduction becomes even more problematic. Are all people rational utility-maximizers? Are all capitalists cynical appropriators of labor? These are important insights about human nature, but they leave out a lot of what there is to know about people, and they aren't true in all times and places.

The particular is especially important to planners. We work in specific places and at specific times. This makes the problems we deal with different from other places in significant ways, and these differences are difficult to quantify. People in Berkeley, California, are motivated in different ways than people in the rest of the country, they have a far different history, and so on. Qualitative methods make the more "humanist" side of society more visible.

I don't think that means that different places can't learn from each other. But it does mean there's a limit to one-size-fits-all thinking. That's the most important insight the post-modernists have.