Click here to close now.

Welcome!

XML Authors: Carmen Gonzalez, Elizabeth White, Asad Ali, Adrian Bridgwater, Dana Gardner

Related Topics: XML

XML: Article

Soft Issues Surrounding Industry Standard Schemas

Soft Issues Surrounding Industry Standard Schemas

It sounds so easy. First, get a bunch of people together who share a common need to interchange some type of data - say, invoices. Explain XML to them. Explain the significant technical benefits of having an industry standard schema for invoices.

Get technically minded individuals into a room with plenty of whiteboards and caffeine. Sometime later they'll emerge with a consensus model of what it is to be an "invoice" enshrined in some schema language (UML/XML Schema/DTD/RelaxNG/whatever).

Thereafter, all interested parties use the schema for data interchange and all is sweetness and light.

This makes 100% technical sense but it often doesn't work in the real world. The reasons it doesn't work have nothing to do with flavors of schema language or indeed flavors of markup language. It often doesn't work because of soft issues concerning people.

Let's start with Zipf's law and the Principle of Least Effort (http://cogsci.umn.edu/millennium/1109153206.html). Simply put, humans strive to do as little as possible to communicate. The language this article is written in, English, is literally riddled with structures that break the rules of English grammar - the schema - in the interests of quick and easy communication.

All human languages exhibit this phenomenon. Successful languages adapt to allow humans to cut corners in the interest of quicker communications. XML tag languages that don't offer similar functionality are asking for trouble. That trouble can manifest itself in a number of possible ways.

First, users may engage in "tag abuse" - using tags for purposes they weren't intended for because it makes their life easier.

Second, users may create point-to-point side agreements between themselves for simpler communications and convert their simple communications to the official schema only when forced to.

Third, users may lobby for "flexibility" that allows them to make local modifications to the industry standard schema, thus creating an entire family of mutually incompatible but similar languages that start as patois and grow into full-blown, mutually incompatible dialects.

Fourth, users may bring the standard initiative down. If this happens, everything from the coffee to the schema language can be blamed. Everything, that is, except noncompliance with Zipf's Principle of Least Effort.

Then there's the matter of organic schema growth and what I call the "tag bag syndrome."

Successful languages, and XML-based tag languages are no exception, need to exhibit the ability to change and evolve over time. Otherwise they atrophy and eventually die. With human languages we just change their grammatical structures and idioms without worrying about historical material fitting the new forms. In other words, we aren't worried about backward compatibility.

With XML tag languages we're typically very worried about backward compatibility. When we need to modify a schema to cater to a new phenomenon, we cannot allow previously valid documents to become invalid. As a result, we loosen the constraints in the schema. Over time, the gradual loosening of constraints erodes the tight control over structure the schema designers put there in the first place. The result is a bag of tags - structures of the form "X can consist of any number of A or B or C or...." In DTD terminology these are known as repeating OR groups.

This leads us nicely to the next soft issue: George Miller's law concerning the cognitive limits of human beings. If you present humans with a list of more than seven options to choose from at any one time, they'll start to feel overloaded and uncomfortable. When it comes to creating XML conforming to a "bag of tags schema," there can be an overwhelming feeling of drowning in a sea of options.

In the back office the software developer is similarly overwhelmed because the large number of choices at each point in the schema translates into a programmer's worst nightmare. known as an exploding state space.

Schema creators ignore Miller's rule at their peril. User and software developers alike can and will subvert the technically elegant designs in order to work within comfortable cognitive limits.

It's important to remember that the "group of people getting together to agree on a data interchange standard" phenomenon is not a new one. Stepping back just one generation, this went on wholesale in the SGML world - without much success. It wouldn't be good soft-issue tactics for me to mention any failed standards initiatives by name. You'll find plenty of evidence if you read through some history of the SGML years, especially the early-to-mid-'90s.

My contention is that the failed industry-standard schema initiatives of the past did not fail for technical reasons; they failed for human reasons. There is a rich lore of experience here that the new wave of XML schema designers could do worse than mine for valuable insights. Those that don't learn from the mistakes of the past truly are doomed to repeat them.

Apart from paying due regard to history, I think XML schema design needs to take a leaf out of the extreme programming book. Start with the customer (human), do the smallest thing than can possibly work, and start using it. Never lose sight of the human creating the XML content or the human writing software to process the content. Remember Miller's law. Remember Zipf's law. Allow the schema to grow/evolve organically over time. It will anyway, whether the schema designer likes it or not.

The only industry standard schemas still standing at the end of this decade will be the ones that address the soft issues.

More Stories By Sean McGrath

Sean McGrath is founder and CTO of Propylon, one of Ireland's fastest growing software companies. Headquartered in Dublin, with development centers in Sligo, Ireland and Mumbai, India, Propylon delivers what it terms "industrial strength XML" and XML consultancy services to its service and product partners in Europe and the United States.

Comments (0)

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


@ThingsExpo Stories
GENBAND has announced that SageNet is leveraging the Nuvia platform to deliver Unified Communications as a Service (UCaaS) to its large base of retail and enterprise customers. Nuvia’s cloud-based solution provides SageNet’s customers with a full suite of business communications and collaboration tools. Two large national SageNet retail customers have recently signed up to deploy the Nuvia platform and the company will continue to sell the service to new and existing customers. Nuvia’s capabilities include HD voice, video, multimedia messaging, mobility, conferencing, Web collaboration, deskt...
The WebRTC Summit 2014 New York, to be held June 9-11, 2015, at the Javits Center in New York, NY, announces that its Call for Papers is open. Topics include all aspects of improving IT delivery by eliminating waste through automated business models leveraging cloud technologies. WebRTC Summit is co-located with 16th International Cloud Expo, @ThingsExpo, Big Data Expo, and DevOps Summit.
SYS-CON Media announced today that @WebRTCSummit Blog, the largest WebRTC resource in the world, has been launched. @WebRTCSummit Blog offers top articles, news stories, and blog posts from the world's well-known experts and guarantees better exposure for its authors than any other publication. @WebRTCSummit Blog can be bookmarked ▸ Here @WebRTCSummit conference site can be bookmarked ▸ Here
SYS-CON Events announced today that Cisco, the worldwide leader in IT that transforms how people connect, communicate and collaborate, has been named “Gold Sponsor” of SYS-CON's 16th International Cloud Expo®, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. Cisco makes amazing things happen by connecting the unconnected. Cisco has shaped the future of the Internet by becoming the worldwide leader in transforming how people connect, communicate and collaborate. Cisco and our partners are building the platform for the Internet of Everything by connecting the...
Temasys has announced senior management additions to its team. Joining are David Holloway as Vice President of Commercial and Nadine Yap as Vice President of Product. Over the past 12 months Temasys has doubled in size as it adds new customers and expands the development of its Skylink platform. Skylink leads the charge to move WebRTC, traditionally seen as a desktop, browser based technology, to become a ubiquitous web communications technology on web and mobile, as well as Internet of Things compatible devices.
SYS-CON Events announced today that robomq.io will exhibit at SYS-CON's @ThingsExpo, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. robomq.io is an interoperable and composable platform that connects any device to any application. It helps systems integrators and the solution providers build new and innovative products and service for industries requiring monitoring or intelligence from devices and sensors.
Wearable technology was dominant at this year’s International Consumer Electronics Show (CES) , and MWC was no exception to this trend. New versions of favorites, such as the Samsung Gear (three new products were released: the Gear 2, the Gear 2 Neo and the Gear Fit), shared the limelight with new wearables like Pebble Time Steel (the new premium version of the company’s previously released smartwatch) and the LG Watch Urbane. The most dramatic difference at MWC was an emphasis on presenting wearables as fashion accessories and moving away from the original clunky technology associated with t...
Docker is an excellent platform for organizations interested in running microservices. It offers portability and consistency between development and production environments, quick provisioning times, and a simple way to isolate services. In his session at DevOps Summit at 16th Cloud Expo, Shannon Williams, co-founder of Rancher Labs, will walk through these and other benefits of using Docker to run microservices, and provide an overview of RancherOS, a minimalist distribution of Linux designed expressly to run Docker. He will also discuss Rancher, an orchestration and service discovery platf...
SYS-CON Events announced today that Akana, formerly SOA Software, has been named “Bronze Sponsor” of SYS-CON's 16th International Cloud Expo® New York, which will take place June 9-11, 2015, at the Javits Center in New York City, NY. Akana’s comprehensive suite of API Management, API Security, Integrated SOA Governance, and Cloud Integration solutions helps businesses accelerate digital transformation by securely extending their reach across multiple channels – mobile, cloud and Internet of Things. Akana enables enterprises to share data as APIs, connect and integrate applications, drive part...
SYS-CON Events announced today that Vitria Technology, Inc. will exhibit at SYS-CON’s @ThingsExpo, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. Vitria will showcase the company’s new IoT Analytics Platform through live demonstrations at booth #330. Vitria’s IoT Analytics Platform, fully integrated and powered by an operational intelligence engine, enables customers to rapidly build and operationalize advanced analytics to deliver timely business outcomes for use cases across the industrial, enterprise, and consumer segments.
SYS-CON Events announced today that Solgenia will exhibit at SYS-CON's 16th International Cloud Expo®, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY, and the 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. Solgenia is the global market leader in Cloud Collaboration and Cloud Infrastructure software solutions. Designed to “Bridge the Gap” between Personal and Professional Social, Mobile and Cloud user experiences, our solutions help large and medium-sized organizations dr...
SYS-CON Events announced today that Liaison Technologies, a leading provider of data management and integration cloud services and solutions, has been named "Silver Sponsor" of SYS-CON's 16th International Cloud Expo®, which will take place on June 9-11, 2015, at the Javits Center in New York, NY. Liaison Technologies is a recognized market leader in providing cloud-enabled data integration and data management solutions to break down complex information barriers, enabling enterprises to make smarter decisions, faster.
Cloud is not a commodity. And no matter what you call it, computing doesn’t come out of the sky. It comes from physical hardware inside brick and mortar facilities connected by hundreds of miles of networking cable. And no two clouds are built the same way. SoftLayer gives you the highest performing cloud infrastructure available. One platform that takes data centers around the world that are full of the widest range of cloud computing options, and then integrates and automates everything. Join SoftLayer on June 9 at 16th Cloud Expo to learn about IBM Cloud's SoftLayer platform, explore se...
@ThingsExpo has been named the Top 5 Most Influential M2M Brand by Onalytica in the ‘Machine to Machine: Top 100 Influencers and Brands.' Onalytica analyzed the online debate on M2M by looking at over 85,000 tweets to provide the most influential individuals and brands that drive the discussion. According to Onalytica the "analysis showed a very engaged community with a lot of interactive tweets. The M2M discussion seems to be more fragmented and driven by some of the major brands present in the M2M space. This really allows some room for influential individuals to create more high value inter...
The world's leading Cloud event, Cloud Expo has launched Microservices Journal on the SYS-CON.com portal, featuring over 19,000 original articles, news stories, features, and blog entries. DevOps Journal is focused on this critical enterprise IT topic in the world of cloud computing. Microservices Journal offers top articles, news stories, and blog posts from the world's well-known experts and guarantees better exposure for its authors than any other publication. Follow new article posts on Twitter at @MicroservicesE
SYS-CON Events announced today the IoT Bootcamp – Jumpstart Your IoT Strategy, being held June 9–10, 2015, in conjunction with 16th Cloud Expo and Internet of @ThingsExpo at the Javits Center in New York City. This is your chance to jumpstart your IoT strategy. Combined with real-world scenarios and use cases, the IoT Bootcamp is not just based on presentations but includes hands-on demos and walkthroughs. We will introduce you to a variety of Do-It-Yourself IoT platforms including Arduino, Raspberry Pi, BeagleBone, Spark and Intel Edison. You will also get an overview of cloud technologies s...
SYS-CON Events announced today that SafeLogic has been named “Bag Sponsor” of SYS-CON's 16th International Cloud Expo® New York, which will take place June 9-11, 2015, at the Javits Center in New York City, NY. SafeLogic provides security products for applications in mobile and server/appliance environments. SafeLogic’s flagship product CryptoComply is a FIPS 140-2 validated cryptographic engine designed to secure data on servers, workstations, appliances, mobile devices, and in the Cloud.
Containers and microservices have become topics of intense interest throughout the cloud developer and enterprise IT communities. Accordingly, attendees at the upcoming 16th Cloud Expo at the Javits Center in New York June 9-11 will find fresh new content in a new track called PaaS | Containers & Microservices Containers are not being considered for the first time by the cloud community, but a current era of re-consideration has pushed them to the top of the cloud agenda. With the launch of Docker's initial release in March of 2013, interest was revved up several notches. Then late last...
SOA Software has changed its name to Akana. With roots in Web Services and SOA Governance, Akana has established itself as a leader in API Management and is expanding into cloud integration as an alternative to the traditional heavyweight enterprise service bus (ESB). The company recently announced that it achieved more than 90% year-over-year growth. As Akana, the company now addresses the evolution and diversification of SOA, unifying security, management, and DevOps across SOA, APIs, microservices, and more.
After making a doctor’s appointment via your mobile device, you receive a calendar invite. The day of your appointment, you get a reminder with the doctor’s location and contact information. As you enter the doctor’s exam room, the medical team is equipped with the latest tablet containing your medical history – he or she makes real time updates to your medical file. At the end of your visit, you receive an electronic prescription to your preferred pharmacy and can schedule your next appointment.