At 03:58 PM 1/30/00 -0500, Mark Guzdial wrote:
>This was a great article -- thanks for posting it, Marcus!  The authors 
>did a VERY careful job with the experimental design and the 
>evaluation.  This is the first serious empirical effort I'd seen on 
>measuring the value of types.
>
>Unfortunately, a well-controlled experiment usually means a pretty narrow 
>finding, and that seems to be the case here.  The main finding here is 
>that programmers who used a more strongly typed C (ANSI C) made fewer type 
>errors when connecting with a library that had typed interfaces (Motif) 
>than programmers using a less strongly typed C (K&R C).  The point is well 
>made and well supported, but it doesn't answer all of the typing issues. 
>For example, it's not true that they made fewer overall errors -- there 
>was no significant difference between the groups on severe errors that 
>were not related to type.

It's also a different question than the one we've been talking about here. 
For myself, I have absolutely no doubt that enforced typing in ANSI C is an 
enormous improvement over K&R C's lack of typing. However, that doesn't 
necessarily imply that static typing of the form used in e.g. Java is an 
improvement over Smalltalk's dynamic typing, and in fact I don't believe 
that assertion. Nevertheless, it's nice to at least see a rigorous 
experiment, even if it's attempting to prove something different.


--
Alan Knight [|]			knight at acm.org
The Object People         	613.225.8812(v)   613.225.5943(f)