Nick Gall's Weblog

Friday, September 12, 2003

The Internet Book Race. "When it comes to books, Internet selling has not led to uniformly low prices. By Virginia Postrel." Interesting analysis. When Amazon raises prices by X, it loses a smaller percentage of customers than Barnes and Noble does when it raises prices by X. This implies there is something besides price that users value about Amazon. Let's call it "BRAND." 8:57:23 AM

Binary XML Standard Considered Harmful --Followup. Omri and I seem to have reached agreement on the appropriate degree of standardization of XML-Infoset serializations. See my prior response to Omri for background. I repost my comments here: Omri, thanks for the clarification. As long as you agree that domain-specific XML-Infoset-serializations (wow, thats a mouthfull) are a good idea, then we are in complete agreement. I completely agree that XML 1.0 (and its descendents, 1.1, etc.) should be the one and only UNIVERSAL XML-Infoset-serialization that spans (interoperates across) all domains. Why? because as your discussion illuminates, an "optimized universal" serialization is an oxymoron because optimization is always relative to a domain-specific set of concerns. 5:31:55 AM

Wednesday, September 10, 2003

Layer Six and AOP. I finally found someone making the link between Aspect-Oriented Programming (AOP) and SOAP: Carlos E. Perez! I repost my comments here: Hurrah! Someone is at least mentioning the conceptual unity of AOP and SOAP. Just as AOP software architectures enable "separation of concerns" based on the concept of interceptors, so too the SOAP envelope-processing architecture is based on "SOAP intermediaries" processing SOAP headers. Each header (or set of related headers) deals with a distinct set of concerns. Thus the WS-Security header deals with security concerns, while the WS-Coordination header deals with state management concerns. No question that aspect-oriented architecture (or should the more general term be "separation of concerns -SOC- architecture") is emerging in various domains to deal with the dramatic increase in complexity driven by the increasing number of "first-class" concerns. Concerns such as security, performance, extensibility, availability, deployability, monitorability, which are dealt with by different software architectures in different ways, but which can be unified by SOAP's ability to deal with federated separation of concerns. Is anyone else discussing how AOP and SOAP are just different "aspects" of architecting for SOC? I mentioned my inability to find such discussion in blog back in July. See http://radio.weblogs.com/0126951/2003/07/11.html . 10:09:48 AM

Binary XML Standard Considered Harmful --NOT! Omri Gazitt has a thoughful piece on Binary XML, but I disagree with his conclusions. I repost my comments here: (Thanks for the pointers to the work underway on Binary XML.) I completely agree with your argument against one universal binary standard, but "not one" does not imply infinite. That is, I think it would be useful to have a handful of "binary XML" standards which more or less cover (80/20 rule) the major scenarios within the three major axes. Of course, the market will eventually discover such "standards" on its own, but standards work could speed things up a bit. Certainly standardizing a compressed, but simple to deserialize, XML for portable devices makes sense? Another standard would be the gzipped XML 1.0 serialization. All that's needed here is to standardize the nitty gritty details of using the two standards in conjunction; something that WS-I should probably tackle. I also think an XML to ASN.1 standard would be useful, just to cover interoperability between the two standards (a lot of management protocols use ASN.1). A few other serialization standards probably make sense as well, but you get the idea. In my experience, the hugely successful standards all share the hourglass shape of a "spanning layer" (see http://radio.weblogs.com/0126951/2003/08/12.html#a33 or google the term). That is, they map down onto diverse implementations (in this case serializations) and map up into diverse applications (seemly infinite for XML Infosets). The Internet, Ethernet, SCSI, etc. standards have this shape. Currently, the XML set of standards lack this hourglass shape because they must serialize into the XML 1.0. Instead, they look like an inverted triangle (narrow base and wide top). Such an hourglass shape enables a standard to adapt both to new implementation technologies and new applications. I believe the heart and soul of the XML family of standards is the Infoset, NOT the XML 1.0 serialization. XML 1.0 was the ladder we all needed to climb to get to a universal agreement on a universally interoperable data structure, the Infoset. Now that we have such a level of agreement, we don't need the ladder anymore--at least not it exclusively. 6:40:55 AM

Monday, September 08, 2003

User Innovation. Given my belief that it is the role of the developer-user that is essential to "open development" (which I will discuss later), I was pleased to come across the following MIT web site: userinnovation: Empirical research is finding that users rather than manufacturers are the actual developers of many or most new products and services - and that they are a major locus of innovative activity in the economy. This finding opens up new questions and avenues for exploration in fields ranging from economics to management of technology to organizational behaviour to marketing research. Examples are patterns in innovation by users, characteristics of innovating users, design of a user-centered innovation process, economics of a distributed innovation process that includes users as innovators, and social welfare implications of innovations by users. [Emphasis added] I find this view to fit my own experience extremely well. It is often users of a business application that see its limitations and are inspired to build a new application that better fits the business they came from. I just started the paper "Profiting from Voluntary Information Spillovers: How Users Benefit by Freely Revealing Their Innovations". 3:40:30 PM

Donald Davidson Obituary. Dr. Davidson wrote his dissertation on Plato's "Philebus," a dialogue between Socrates and Philebus, one of his many foils, a lengthy defense of the superiority of intellectual activity over physical pleasure. Dr. Davidson told Mr. Lepore that he thought Quine was perplexed over why he chose such an antiquated topic, but kept it to himself. This is really going to bug me now...So I just went off and looked into it while writing this entry. In tracking this down, I stumbled across the following set of links on Davidson (see #18). Apparently the movie, The Thirteenth Floor, references Davidson! Of course the link is now dead, but Google to the rescue, with a cached page describing why Philebus is relevant. It seems to be an excerpt from this bio. I guess I'll have to go and read Philebus now...In his honor. (I wonder if Project Gutenberg has it...) 4:31:58 AM