We are conducting a content analysis on Development Communication research in our school. Our aim is to look at what social issues DevCom students tackled in their research paper. Do we need two coders or is it possible to only have one?
A lot depends on whether you are planning on publishing your work and if so where.All too often, reviewers will insist on an assessment of the reliability for your coding even when the coding system is quite straight forward.
One compromise is to have a second coder work on only a subset of the data, say 10% or 20%.
If the categories are easy for identifying, you could allow a computer to do it. This is like the instructions that you give coders before they start coding, but if you can be really precise then getting a computer to do it should be straightforward (perhaps finding someone to code). If you cannot be that precise, then there likely is room for human variability, so like David L Morgan says, it would be good to have at least some rated by multiple people.