Cem Kaner is one of the few researcher / educators out there that focuses on Software Quality Assurance full-time.
I ran across this article (linked below) where he talks about metrics. Here is the final slide, but you'll want to review the whole thing to get the details.
4 Things to Remember1. Yes, most software metrics are (to some degree) invalid.
However, that doesn’t reduce the need for the information we are
trying to get from them.
2. I think it’s part of the story of humanity that we’ve always worked
with imperfect tools and always will. We succeed by learning the
strengths, weaknesses and risks of our tools, improving them
when we can, and mitigating their risks.
3. We need to look for the truths behind our numbers. This involves
discovery and cross-validation of patterns across data, across
analyses, and over time. The process is qualitative.
4. Qualitative analysis is more detailed and requires a greater
diversity of skills than quantitative. Qualitative analysis is not a free
(or even a cheap) lunch. We evaluate the quality of quantitative
measures by critically considering their validity. An equally
demanding evaluation for qualitative measures considers their