Re: Languages don't matter. A mathematical refutation

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

On Thu, 2 Apr 2015 07:48:45 -0700 (PDT), jm.tarrasa@gmail.com wrote:

> El jueves, 2 de abril de 2015, 15:36:02 (UTC+2), Dmitry A. Kazakov  escribió:
>> On Thu, 2 Apr 2015 05:59:03 -0700 (PDT), brbarkstrom@gmail.com wrote:
>> 
>>> To change the subject a bit, is there any possibility of using
>>> the probabilistic approach to estimating the long-term cost of
>>> maintenance given a history of errors with a particular language?
>> 
>> since errors made in C are different from
>> errors made in Ada. You change the language, you get *other* errors, no
>> statistics across to compare.
>> 
>> Or taking another path, considering "probabilities" of same error made in C
>> and Ada. Again,
>> ...
>> Apples and oranges all the way.
> 
> You can create a criteria valid for any error or language
> 
> A) Severity
>  1) Data lost
>  2) Crash
>  3) ...
>  4) Inconvenience
> B) Frequency
>  1) each day
>  2) One a week
>  3)...
> C) Time needed to fix it (hours)
> 
> Score= ((Severity * K1) * (Frequency * K2)) + Time * K3
> 
> Or whatever formula you want to come with. Calculate the errors of several
> similar projects and you have an statistic.

Throwing together coefficients does not make it statistic. In fact,
whatever algebraic function of non-random variables you take the result is
still non-random. This is a trivial fact. So coefficients and
multiplications change nothing.

You must start with showing that "severity", "frequency" etc are random
variables. There is a clear definition of what a random variable is. It is
a measurable function from the set of elementary outcomes. The first step
is presenting the set.
 
-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de