A topic in research methodology
Coding is usually the first phase in data analysis of qualitative data, where codes are assigned to features in the data.
The origin of the codes used is usually distinct in confirmatory research (where predetermined codes are often derived form the conceptual framework before data collection), and in discovery research (such as in grounded theory studies) where the codes are derived from the data itself: open coding.
Read about:
My introduction to educational research:
Taber, K. S. (2013). Classroom-based Research and Evidence-based Practice: An introduction (2nd ed.). London: Sage.
