Good link. The thing that stands out to me about the standard code metrics used in studies like this, is that they attempt to measure actual complexity, rather

Good link. The thing that stands out to me about the standard code metrics used in studies like this, is that they attempt to measure actual complexity, rather than perceived complexity. LOC perhaps is the only measure that directly measures perceived complexity. If I add 100 lines of code to my project, its possible that cyclomatic complexity stays constant (I didn't add any branches, just a straight fall through), but the perception of complexity no doubt increased. If we can come up with more metrics that are based on our perception of a codebase's complexity, I think we would see interesting results.