I've read and understood the reference I've provided (Bossavit), and I've also read and understood the reference justin_vanw provided (McConnell), so no, I'm not quoting Bossavit blindly.
After reading both, I found Bossavit much more convincing. In addition to meticulously following the chains of references back to the original research, Bossavit also examines how science is done and what is required in order for a claim to become established scientific fact. His conclusion is that the evidence for the 10x claim is "quite weak."
Here's my summary of his material from the last time this came up ( https://news.ycombinator.com/item?id=4118034 ). There's much more to Bossavit's research than my quotes here, so if you disagree, please read and rebut his work directly, not just these quotes.
"How strong is the support conferred to the 10x claim by the best-reputed list of references, for a reader persistent enough to follow the chain of citations back to primary sources?
"Based on our close reading of the “10x files”, we can now answer: quite weak.
"Not a single one of the references is to a replication, in the scientific sense of the term, of the original exploratory experiment.
"The empirical data is in general quite old, most if not all of it predating widespread use of the Internet - which we can safely expect to have wrought major changes in programming practice.
"None of the studies address the question of construct validity, that is, how meaningful it is to speak of an individual programmer’s productivity, and if it is meaningful, whether the experimental measurements line up adequately with that meaning." [1]
[1] The Leprechauns of Software Engineering explores what science is and how we distinguish between fact and folklore in software engineering. It specifically explores the 10x claim, and determines that it's folklore. http://leanpub.com/leprechauns
I was using "research" in the colloquial sense, not in the "research paper" sense. Bossavit researched the 10x claims (thoroughly and meticulously) and wrote up his findings in the book I mentioned. You can find it here: http://leanpub.com/leprechauns
It's an impressive work of scholarship; many of the citations he followed were out of print, expensive, or referring to unnamed parts of 300-page books. Luckily for us, Bossavit's write-up is engaging and accessible.
It isn't free, but it's trivially inexpensive (US$5-10) if you care about this subject. Far cheaper than the source material.
And isn't available in any of the linked libraries available to me.
And I already had a long email discussion with Laurent back in 2011, about his comments on Steve McConnell's blog.
If I may make a suggestion, when the source material is likely to be unavailable, it might be better to quote the reasons given rather than the conclusions -- then we can try to follow the reasoning rather than having to take someone's conclusions at face value.
I don't understand what you're getting at here. Laurent's book (written after McConnell's blog) is available at http://leanpub.com/leprechauns . If you're unable or unwilling to figure that out, I suspect you're not really trying.
You're engaging in an asymmetric attack here--posting trivial statements that avoid the substance of my comments, but require me to do a lot of work to satisfy you. I've replied to your comments in good faith. Now the onus is on you.
I wasn't engaging in any kind-of attack, just making a suggestion.
You said -- "if you disagree, please read and rebut his work directly, not just these quotes" -- so, as I haven't read the book, I haven't tried to rebut those quotes.
Steve McConnell himself doesn't dispute Bossavit's claims about the earlier studies (for the most part), he just disagrees about the significance of those claims. See McConnell's rebuttal in which he acknowledges the methodological weaknesses of the citations: http://www.construx.com/10x_Software_Development/Origins_of_... .
Sure - I'm pointing to the section titled "A Deeper Dive into the Research Supporting '10x'".
I'm accepting one of Bossavit's claims on trust: he says that of McConnell's eight citations in support of the 10x claim, only two were original research based on empirical studies under controlled conditions (and of those two one only concerned debugging).
I'm willing to trust that because it looks like McConnell mostly agrees. For example, regarding the 1986 Curtis paper, McConnell writes "Bossavit states that, “the 1986 Curtis article does not report on an empirical study.” I never stated that Curtis 1986 was an 'empirical study.'" Regarding DeMarco and Lister, he says "Editorial insinuations aside, that is a correct description of what DeMarco and Lister reported, both in the paper I cited and in Peopleware. Their 1985 study had some of the methodological limitations Sheil’s discussed in 1981".
They disagree about what counts as evidence supporting the 10x claim, but apart from the Card 1987 citation (about which Bassavit was wrong), McConnell confirms Bossavit's claims about every citation.
After the words you quote, McConnell goes on to say -- "Having said that, their study supports the 10x claim in spades and is not subject to many of the more common methodological weaknesses present in other software engineering studies."
After the words you quote, McConnell goes on to say -- "Bossavit should have looked at the paper I cited, not the book. The paper shows a 5.6x difference between the best and worst programmers—among the programmers who finished the assignment. About 10% of the programmers weren’t able to complete the assignment at all."
I don't see how that can be described as McConnell mostly agrees?
I was originally responding to the challenge "aren't you taking Bossavit's claims on trust?"
I'm differentiating between Bossavit's claims about the citations from Bossavit's analysis and arguments. I have to take his claims about the articles and books on trust, because I haven't read them. On the other hand, I don't have to trust his analysis and arguments - I can evaluate those on my own.
In the case of DeMarco and Lister, for example, Bossavit writes "the only 'studies' reported on therein are the programming contests organized by the authors, which took place under loosely controlled conditions (participants were to tackle the exercises at their workplace and concurrently with their work as professional programmers)"
That's the only claim that I have to trust here. Everything else is analysis. McConnell agrees with that description of the citation, but disagrees that it invalidates DeMarco and Lister's research. He thinks that a programming contest that took place under loosely controlled conditions is a legitimate research study.
"I am claiming that for whatever reasons he is here dressing up, in the trappings of scientific discourse, what is in fact an unsupported assertion meshing well with his favored opinion. McConnell is abusing the mechanism of scientific citation to lend authority to a claim which derives it only from a couple studies which can be at best described as “exploratory” (and at worst, maybe, as “discredited”)."
-- as Bossavit's "analysis and arguments" which you can evaluate for yourself.
I've just read through the McConnell post and the comment stream, and your comment that "McConnell confirms Bossavit's claims about every citation" baffles me :-)
"Curtis 1986. ... Bossavit says the paper “offers no support for the ‘10x’ claim.” But the first paragraph in section II.A. of the paper (p. 1093) summarizes 4 studies with the overall gist of the studies being that there are very large differences in productivity among programmers. The specific numbers cited are 28:1 and 23:1 differences."
I don't see how that can be described as McConnell confirming Bossavit's claims?
Again, McConnell isn't disagreeing with Bossavit's claims about the Curtis 1986 citation. He concurs! "I never stated that Curtis 1986 was an 'empirical study.' Curtis 1986 is a broad paper that touches on, among other things, differences in programmer productivity. "
The difference is that McConnell thinks that summarizing four studies "offers support for the 10x claim" and Bossavit does not. That's a matter of analysis & evidentiary standards.
