Re: Languages don't matter. A mathematical refutation

["Jean François Martinez" <darkquark99@gmail.com>]

On Friday, March 27, 2015 at 6:36:51 PM UTC+1, Dmitry A. Kazakov wrote:
> On Fri, 27 Mar 2015 04:25:21 -0700 (PDT), Jean François Martinez wrote:
> 
> > On Thursday, March 26, 2015 at 4:21:45 PM UTC+1, Dmitry A. Kazakov wrote:
> >> On Thu, 26 Mar 2015 06:43:01 -0700 (PDT), Maciej Sobczak wrote:
>
> > Really?  Text books on statistics are choke a full of similar examples and
> > exercises like comparing the proportion of defective products at
> > manufacting plant A and B then checking the null hypothesis before
> > deciding that A's products are better.
> 
> It is not similar. A production process is a physical one of which we know
> that the behavior is stochastic because the laws of physics are (e.g. laws
> of thermodynamics are statistical).
> 

I think you have an incorrect vision of probability;  "Probability
is a measure of our ignorance: the flipping of a coin is not random.  It is
just that we are unable to control our gesture";  from a book on probabilities I read when I was young.   

On the other hand if that night someone had not phoned your parents they would have gone to bed five minutes earlier, it would have been a different spematozoid and you would be Natalia Kazakova the pianist.  

For the output of a manufacturing plant it is subject on fluctuations for
such motives like operator lacking sleep because his baby is 
growing teeth. 


> A developing team is not governed by these laws, because decision making is
> not random and the system as a whole has memory (people learn in process).
> 
> > In our case we have a random
> > variable and that is group 
> > quality.
> 
> How is this random? A given group has given quality. It is nowhere random:
> if you measure the quality repeatedly you will get same quality.
> 
> > And it is common in this field to assume taht your population is a sample
> > of an infinitely-sized conceptual population.
> 

Are students of identical quality?  And all groups have the same synergy or lack of it?  If one of this answer is no.  Than we can apply probabilities on 
this problem just like we do for the actually non random problem of coin flipping.


> Which is a way different model. If you randomly select a team, all
> randomness is not in the team but in the selection process. For this to be
> correct you should show that selected teams are equivalent in terms of
> given SW metrics. It would be quite difficult to do because students have
> different exposures to programming, everything is changing and you cannot
> "recycle" teams.
> 

See above for coin flipping and apply it tpo groups.   We don't control the factors involved in success or failure for programming groups.  Just like
for coin flipping.  And like for cpoçing flipping we can apply probabilities and confidence intervals to sets of groups.  


> So what? Why should this imply anything for SW processes as
> performed by professionals?


This is a valid objection.  One I had thought about while thinking about the
imlplications of Prpofessor McCormick's experience and forgot to include: it  only telle us about performance at a certain level of experience.   Of corse we
could tell to people who say "MLnaguages don't matter" that they didn't 
restrict the set to "programmers having graduated" but statisticiand don't
say that they tell "Futher study is necessary for progra


> 
> Again, we know Ada is better for that. But this study would not show any
> casualty or statistically proven correlation between both. It is nothing
> more than a "by-the-way" argument from the statistical POV.
> 
> -- 
> Regards,
> Dmitry A. Kazakov
> http://www.dmitry-kazakov.de