Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!think.com!zaphod.mps.ohio-state.edu!swrinde!cs.utexas.edu!uunet!visix!ip2020!adamksh From: adam@visix.com Newsgroups: comp.software-eng Subject: Re: Metrics Example Message-ID: <1991May25.171824.22845@visix.com> Date: 25 May 91 17:18:24 GMT References: <24600@unix.SRI.COM> <1991May23.231339.22418@netcom.COM> <1991May24.201741.14138@netcom.COM> Sender: news@visix.com Reply-To: adam@visix.com Organization: Visix Software Inc., Reston, VA Lines: 39 In article <1991May24.201741.14138@netcom.COM>, jls@netcom.COM (Jim Showalter) writes: >We think they're real because project in trouble tend not to have any >metrics, and projects on schedule tend to use metrics. As for WHY we >think they work, this is just the causality issue again--I'm personally >not particularly concerned with why the metrics work: I'm concerned >with them working, and that's about it. This argument in favor of metrics shows precisely what is wrong with non-causal correlations. This is a familiar problem in social science. For example, students at private schools generally perform better. Students in more wealthy neighborhoods do better. Asian students do better. Therefore, to improve your child's performance, send them to private school, or move into a wealthy neighborhood, or make them Asian. This is faulty reasoning. The greatest cause of good performance in school is parents who take an interest in their child's education. If you care enough to spend extra money or move to a better neighborhood for the sake of your child, then your child has the advantage of supportive parents. The actual act of spending money or moving is irrelevant next to the will to do so. If you send your child to private school in order to get rid of him, then he's in trouble. Let me restate the analogy. When a project manager cares enough about his project to try metrics for improving quality, then regardless of the metrics he chooses, the project has an advantage (namely, the manager himself). When a project manager is sick to death of his project and wants to use metrics to save himself some work, then the project is likely to fail. When someone cares about you and your work, you will do better. When someone cares only about the number of lines of code you write, you will do worse. Adam