The constant comparison method isn't restricted to Grounded Theory, and is a frequently applied approach to analysing and exploring qualitative data. It's essentially a really common-sense approach for examining qualitative data...

There are many different ways of coding qualitative data. Two of the most frequently mentioned are in vivo coding, in which participants’ actual words become codes while the researcher is coding, and a priori coding, in which the researcher has defined codes before beginning to analyze the data.

Sometimes content analysis is applied as a blanket term for looking to see what qualitative data is about (ie the content) and from there many approaches can be applied.

Qualitative researchers often try to understand the world by listening to how people talk, but it can be really revealing to look at not just what people say, but how. This is how discourse analysis (DA) can be used to examine qualitative data.