My intent was to clarify (what I perceived to be) the parent's argument, more than make one of my own.
I think if our process is "1) write the software in Java, 2) remove those lines", it's clear that we've probably changed the average bug density of the project. I agree that there is much reason for concern in generalizing that result to what would have happened if we'd written in that other language to begin with.
I think if our process is "1) write the software in Java, 2) remove those lines", it's clear that we've probably changed the average bug density of the project. I agree that there is much reason for concern in generalizing that result to what would have happened if we'd written in that other language to begin with.