Title: Message




Hi 
Folks,
 
I am interested in 
hearing your thoughts on the differences between an information system that is 
extensible versus an information system that is evolvable.
 
For example, suppose 
that Amazon.com gives users the ability to do a keyword search.  
Further, suppose that Amazon empowers its users to create new keywords (and map 
the new keywords to information at the Web site).  Is this support for new 
keywords an example of extensibility or evolution?  By adding new keywords 
has Amazon merely been extended, or 
has it evolved?  
 
Let's take another example.  Suppose that Amazon 
gives users the ability to search by book category (e.g., Fiction, Non-Fiction, 
etc.)  Further, suppose that Amazon empowers its users to create new 
categories (and map the categories to information at the Web site).  Is 
this support for new categories an example of extensibility or evolution?  
By adding new categories has Amazon merely been extended, or has it 
evolved?
 
If adding new keywords and adding new 
categories are merely examples of extension, then can you give an example 
of evolution?   
/Roger