From: Jacob Fugal Date: 2006-09-12T22:46:19+09:00 Subject: Re: The economics of a slow but productive Ruby On 9/12/06, Neil Wilson wrote: > It's rarely a matter of economics and statistics. Essentially there is > very little good scientific data on the relative merits of different > development systems. Practically all you can find was done on > productivity and sociology in development was done in the 70s and early > 80s. I'll actually agree with you here as well. My email actually started out in a much different direction, which is when I wrote that disclaimer. The disclaimer escaped editing however when the body of the email changed. When I refer to "objective facts", I am referring to the derivation of the equation in general, not specific values. When I started the email I never intended to delve into placing specific values on X and Y. My primary intent was just to examine the equation that could result in the abstract. This was to demonstrate that a boolean choice can be made, but *only* if the party making the choice is willing to decide on values for X and Y (and Z). Values for X can be locked down for any given choice. The important thing is that the X you use be related to your situation. There is no one size fits all X -- in some cases X will be significant (number crunching) in others it might be nearly 1. That determination needs to be made on a per project basis. Values for Y on the other hand are very subjective. As you said, there is very little if any hard scientific data (in the form of published studies) to support any value of Y. Most of what we have is anecdotal. *But*, if a decision maker has experienced some of those anecdotes him/herself, or is willing to accept the judgment of another in evaluating those anecdotes, they can determine a Y value that they are willing to believe for the sake of the decision. My purpose was never to propose that certain values of X or Y are correct, but rather to provide a framework equation inside which different values of X and Y can be examined. Jacob Fugal