On yesterday’s Project VRM conference call, a piece of the Vendor Relationship Management puzzle snapped into alignment in a flash of insight.
It wasn’t something new to the movement, rather it was a realization about the primacy and criticality of what we are doing and how to communicate it. It has always been a part of the conversation, just one that we often took a bit of time to get around to. And yet, it is perhaps the most important piece of all:
When we put the user at the center, and make them the point of integration, the entire system becomes simpler, more robust, more scalable, and more useful.
This is a profound shift that has some interesting parallels with a concept in AI called “stigmergy” and with a bit of classic Einstein becomes a totally new way to think about next generation systems design. In other words VRM changes the landscape in a way that not only makes life better for individuals, it profoundly improves the information architecture that modern society depends on.
If you’ll indulge me, I’ll try to explain.
User Centrism
VRM has its roots in the user-centric Identity movement and has user-centrism at the core of its DNA. The first, and perhaps most obvious, interpretation of user-centrism is user control. That, unfortunately, is part of the problem.
User Control
User control is critically important. It resonates with the core of the modern social contract. Freedom. Liberty. Capitalism. The Age of Reason. Liberalism. These systems and ideologies all assume that the individual, and only the individual, has legitimate moral authority over his or her life, assets and the disposition of both. These are powerful concepts. So powerful, that when you build systems that provide individual control, you energize vast personal resources that in turn become real economic power, measured in trillions of dollars, just to consider US GDP. Contrast this with fascism, communism, and socialism, which place the state above the individual and in varying forms take control away. There’s some powerful mojo supporting the whole capitalistic freedom-loving democracy thing.
Regulated Freedoms
Of course, unfettered freedom isn’t the ultimate answer. We’ve learned how unregulated markets fail in various ways, often recreating abuses of power that eventually lead back to a loss of individual control. Think Standard Oil. Southern Pacific Railroad. AT&T. All monopolies that abused their power. And they all owe their break-up to the Progressive political movement which itself was an exercise in user control that started in the early 1900s and arguably ended in the 1990s when Clinton “reformed” welfare.
The Political Siren Call
The problem with user control is that it is so powerful as a political concept. “Putting users back in control” is a seductive rallying cry. In fact, it echoes with John Edward’s current populist campaign against poverty as well as Marx’s call to “workers of the world, unite!” The echoes also show up in user centrism in efforts like the Attention Trust, on which I’ve commented before. Much of the Attention Trust work is important, powerful work. But I still don’t know what they mean when they say that people own their attention data. Does that mean we somehow have the right to “nationalize” private data silos in the name of the people? Without debating the politics of this question–there are good points on both sides–it is clear that this line of thinking about VRM, user control, and user rights, is deeply political and therefore, controversial.
The Conflict of Control
It is also challenging to the graceful and speedy realization of our goals. Starting the conversation by asserting user control implies a loss of control somewhere else. Usually that means conflict, as few entities have ever given up control without a fight. So, thinking and talking about putting users in control resonates with users. But it scares the crap out of vendors. Too bad, some people say. Even yesterday, on that same VRM conference call: “We’ll punish them and get them to be more open and more transparent.” We may be able to do just that, but it is unlikely to be the easiest route to realize our goals.
Especially not if there is a way to reframe the conversation, a way to redefine the important matters, such that the debate is not about user control, but rather about the inherent efficiencies and power of user-centrism. If we can do that, then user control gets built into the system automatically and those who would be giving up some of the control they have today–in their precious vendor data silos–do so not out of punishment, but out of honest, natural desires to improve their bottom line. Along that route lies the embrace of vendors and, I believe, more fruitful relationships for everyone.
User Centrism as System Architecture
Doc Searls shared a story about his experience getting medical care while at Harvard recently. As a fellow at the Berkman center, he just gave them his Harvard ID card and was immediately ushered into a doctor’s office–minimal paperwork, maximal service. They even called him a cab to go to Mass General and gave him a voucher for the ride. At the hospital, they needed a bit more paperwork, but as everything was in order, they immediately fixed him up. It was excellent service.
But what Doc noticed was that at every point where some sort of paperwork was done, there were errors. His name was spelled wrong. They got the wrong birthdate. Wrong employer. Something. As he shuffled from Berkman to the clinic to the cabbie to the hospital to the pharmacy, a paper (and digital trail) followed him through archaic legacy systems with errors accumulating as he went. What became immediately clear to Doc was that for the files at the clinic, the voucher, the systems at the hospital, for all of these systems, he was the natural point of data integration… he was the only component gauranteed to contact each of these service providers. And yet, his physical person was essentially incidental to the entire data trail being created on his behalf.
User as Point of Integration
But what if those systems were replaced with a VRM approach? What if instead of individual, isolated IT departments and infrastructure, Doc, the user was the integrating agent in the system? That would not only assure that Doc had control over the propagation of his medical history, it would assure all of the service providers in the loop that, in fact, they had access to all of Doc’s medical history. All of his medications. All of his allergies. All of his past surgeries or treatments. His (potentially apocryphal) visits to new age homeopathic healers. His chiropractic treatments. His crazy new diet. All of these things could affect the judgment of the medical professionals charged with his care. And yet, trying to integrate all of those systems from the top down is not only a nightmare, it is a nightmare that apparently continues to fail despite massive federal efforts to re-invent medical care.
Doc’s insight–and that of user-centric systems–isn’t new. What’s new is the possibility to utilize the user-centric Identity meta-system to securely and efficiently provide seamless access to user-managed data stores. With that critical piece coming into place, we have the opportunity to completely re-think what it means to build out our IT infrastructure.
What clicked on the conference call was first, that this approach actually has some intriguing resonance with a field of AI called “swarm intelligence” and the concept of stigmergy. And second, as a result, the user as the point of integration has the potential to be profoundly different and profoundly more efficient than current practices.
Swarm Intelligence and Stigmergy
Swarm Intelligence looks to the world of insects as inspiration for building AI systems that are collectively smart, but using individually dumb, but active components. For example, how do wasps build nests? Or how do ants find paths to food? It turns out that a lot of these insect behaviors have common properties that can be used to build computer algorithms. One concept that is particularly useful is “stigmergy”, which means marking the environment as communal signaling in a larger, emergent algorithm.
Ants, for example, mark their trails with pheromones. As other ants explore for food, they sometimes follow existing trails, other times not. As more and more ants find success along one particular trail, it gets reinforced, and even improved as some ants’ explorations discover a slightly better route. This natural feedback loop uses the environment in a simple way to allow a bunch of ants to find food in an incredibly efficient way. The last time I looked into it, the Ant Algorithm was in fact the best known algorithm for a particular version of the “Traveling Salesman” problem. Amazing. All without any “active” part of the algorithm actually knowing or thinking about the entire area being mapped–which is what other mapping algorithms basically do.
So what the heck do a bunch of ants have to do with VRM? With a bit of a solipsistic twist and topological imagination, quite a bit.
Albert Einstein helped the world understand the truth that all velocity is relative. That me running at 15 mph towards a stationary car is the same as the car traveling 15 mph towards me. The important thing is the relationship between the parties, not which one is standing still.
Now apply that sense of relativity to “stigmergy” and invert the ant and the environment. (And don’t hurt your brain!)
Instead of thinking of humans as the active element, think of humans as the environment and Vendors as the ants. Instead of humans visiting a bunch of isolated data silos, invert it so that vendors are visiting stationary users–or their stationary data stores.
Now, instead of a bunch of individuals running around leaving a disparate data trail which is hard to keep track of, the individual represents the digital environment where data is stored by vendors. When the next vendor comes along, the data is there, available for use, without the need for complex integration, processing, or systems maintenance, just like the environment is there for the next ant to come along, allowing that ant to do what they do without a complicated brain or sophisticated map of the territory.
It doesn’t matter that Doc was physically moving around in his example. From Doc’s perspective, he was always right there. “No matter where I go… there I am.” This is more than just a solipsistic view of the universe, it is perhaps the most critical insight of the VRM user-centric gestalt. When you put the user at the center, it makes it trivially easy to manage and integrate the entire digital experience of the user. Because it is all right there, all the time.
It is hard for me to judge if that makes any sense to the average person, but when it clicked in my brain yesterday, it was like a mega-watt flash bulb going off. This is a profoundly different way to think about systems architecture. Just like the ant algorithm, it shifts the problem from one of a complicated system that has to know and integrate everything, to one where all the vendor needs to know is which data store goes with which user. The rest follows.
Sure, there is still a lot of work yet to be done. We have to figure out the protocols and technologies for what data vendors actually share in that data-store and how we assure reliable, always-on access in a secure and privacy-protected manner. Fortunately, as I mentioned earlier, the user-centric Identity meta-system is addressing a huge portion of that. In short, we are building on the shoulders of giants, which stand on the mountains of Moore and Gates and Postel and Berners-Lee and Andreeson. Sounds like fun to me.
Assuming they can deal with scaling at a Google or YouTube pace (and it looks like they probably can), their approach to multi-resolution experiences and automated image linking, extraction, & assimilation, truly changes what images mean on the web.
You might think of what they are doing as creating the visual Semantic Web.
I feel the need for some secure, personal repository that would hold all of my connections and “whuffie” together. I want to keep my whuffie in my wallet - but not in a Microsoft Passport/Hailstorm kind of way. Ack, no.
It should include most elements of OpenID, a lot of FOAF, and maybe some of the stuff being worked on by the Attention Trust people.
I want it in XML, of course, and I want it to be incredibly easy to implement and use, as secure as it possibly can be, and extensible without being completely unmanageable.
Naturally, I’d want everyone to adopt it – from eBay to Amazon, Facebook to Flickr, Google to Microsoft to Yahoo.
This is a VRM perspective on reputation and it makes perfect sense (and the rest of the post is worth reading as well).
This immediately triggered an insight: identity seems to be inseparably bifurcated between assertions and reputation, between the direct and the indirect, or in legalese, between the statutory and the case-based. The latter two terms I think are particularly useful.
Reputation is a critical missing piece in the Identity meta-system. The meta-system enables reputation–as infrastructure you can build reputation with it–but I have yet to see good, concrete thinking about how to capture, build, leverage, and work with reputation in a general way. It’s still fairly fuzzy, despite its criticality. It’s a bit like the World Wide Web as a commerce platform in 1992. Sure, you could see how http and html could enable wide-spread e-commerce, but few grokked a future made of SSL, shopping carts, pay-per-click, and affiliate marketing.
Yet, I think that figuring out reputation is required to completely resolve the issues of Identity. Michael’s post focused on the isolated reputation silos at places like eBay and Equifax. And a personal data-store containing our transaction history, feedback, and ratings, is a great start for decentralizing identity, but doesn’t address what makes reputation distinct from other aspects of Identity.
Think about this missing piece as the distinction between statutory and case-based Identity.
I like this reference because it is a useful distinction in the U.S. legal system. Statutory law is what the government explicitly makes law, typically by legislative bills signed by governors or the President. It also includes local city and county ordinances and the like. These are explicit rules, formally enforceable in court.
Case-based law, on the other hand, is based on how the courts have decided to interpret the law, based on all existing applicable statutes and prior case law. It is essentially a case-by-case distillation of the entire history of the jurisdiction in the matter at hand. It requires analysis and evaluation of the entire set of applicable laws and prior judgments, and it is the ultimate arbiter when statutory laws are in conflict, such as when state and federal law disagree.
Think of Identity as a combination of statutory and case-based claims. Since identity, in the Identity meta-system, is the sum of all claims about an entity or individual, I think it behooves us to understand more clearly the distinction between statutory and case-based claims.
So, I’d like to introduce two new terms into the Identity conversation: “Statutory Identity” and “Case-based Identity”.
Statutory Identity
Statutory Identity is based on the explicit assertions of fact made about me by Identity Providers (IDPs) as to my true nature, e.g., that I am a Sun Microsystems employee (I’m not, btw), of a certain age, or a US citizen. These easily fit into the “claims” architecture of the emerging Identity infrastructure, and Relaying Parties can readily judge the validity of a particular claim based on the authority ascribed to the IDP. For example, the Department of Motor Vehicles is arguably definitive regarding my right to drive, authoritative for my age, but not authoritative for my current employment status.
Case-based Identity
In contrast, Case-based Identity is built from the accumulation of transactions (historical facts) or assertions of opinion/judgment by others. It is emergent or generative and is more a matter of judgment than fact. It is our reputation, as rendered by a particular method or by a particular service based on a knowable and refutable set of data. For example, your credit rating is a construct of one of three credit-bureaus, it represents their judgment about your credit worthiness. Rarely do these three sources agree, often because they base their judgment on varying data. Similarly, eBay generates its own reputation ranking based on feedback from transactions at their service. Both of these reputation architectures are (1) based on real transactions (2) refutable through some appeals process.
The good news is that these underlying data points can readily be communicated via the Identity infrastructure. The bad news is that there is as of yet no clear agreement about how to convert those facts into a reputation. Different folks have ideas, but we lack even a clear conceptual framework.
And yet, my identity is clearly both the factual statutory claims about me and the emergent reputation based on my history. While we have developed an architecture for the first, I think we are only beginning to establish a framework for the latter. Perhaps considering reputation as case-based identity, we can start to outline the components required for such case-based systems to work:
transaction data (potentially including opinions of others)
algorithmic evaluation
refutation process
These may not be the definitive requirements for a reputation system, but they seem to be present in the working systems I know of and are perhaps a good starting point.
For the record, I think it is an even bet as to whether or not personal opinions can be effectively integrated as “transaction history” in a case-based identity system, given the challenges of emotions, grudges, slander, and the non-provability of opinions.
It is also a near certainty that for certain types of case-based identity that the user will never be able to actually fully control the data-set. For example, I could significantly improve my credit score if I had read-write control over that data-set. Unfortunately, that would render the current system completely ineffective. Perhaps a new one could emerge, but there are other domains, such as criminal records, etc., where an authoritative reputation requires a data-set with limited or heavily moderated user control–otherwise everyone would erase those pesky traffic violations.
Any suggestions for other elements in a good case-based identity system?
Project VRM is tackling public radio–or more broadly public media–as its first concrete initiative. Put simply, the goal is to double the public contribution to public media in the United States.
In that context, I was intrigued when Neil Gaiman, author extraordinaire–perhaps best known for his seminal work on The Sandman graphic novel–mentioned the PLR (Public Lending Right) in the UK when a reader asked about keeping a digital copy of an audio book they had borrowed from the library:
Would you mind if I kept Coraline on my computer until I buy it, or at least recieve it for some gift-giving occasion?
Thanks for making such a fantastic audiobook, by the way!
-Anna
I don’t mind at all. The disks have to go back to the library because someone else may need them, but I can’t see why you need to have the object in your possession in order to listen to it, whether it’s an MP3 CD or an Audio CD version of the audio book — you aren’t stopping someone else from listening to it. Again, I’d rather that you didn’t pass on your copy to anyone. And I’d like it if the US signed up for PLR. But listen away…
Of course, the libraries have already paid for the audiobook, so Neil and his publisher already were paid once, yet I appreciate his view of fair use as I sense many out there might disagree. But it was the link to PLR that caught my attention.
It turns out that the PLR pays authors based on the lending popularity of their books. So, when people borrow a book in the UK from a public library, it is free, and yet the author and publisher get a small amount of compensation each time it is borrowed.
It is an intriguing approach for how to support authors when their work is freely accessible through public resources. In the UK, this is the result of a 1979 law and state funding–and is a completely separate legal right from copyright–so we probably won’t be seeing it in other countries any time soon. However, I think the structural options might provide some inspiration or guidance to the VRM Public Media initiative. The goal is to make it super easy for individuals to support the programs they like without incurring the overhead and hassle of becoming “members” and enduring fundraising marathons.
Now, of course, radios in the US don’t provide integrated tracking of what we listen to–and I can already hear privacy advocates aiming their well-intended attacks–but VRM could offer a voluntary route for users to say “I like this. Let me pay a little something.” Keeping it voluntary and tied to the actual media being consumed shifts the dynamic from one of tracking everything to tracking the support from people and finding a way to turn that into cash, kudos, or more airtime for the artists/producers. Adding this functionality to real-world radios will take some time, but radio-enabled cell phones already look promising. And adding it to online music software is arguably even easier, once we figure out the right protocols.
This Monday, Doc will be rallying troops again at the Berkman center for a discussion on VRM in the morning, then Public Media & VRM starting around 1pm. I won’t be able to make it, but I look forward to reports from the field.
I’m a big fan of Jeremy’s blog, even if that is where he introduced me to the most time consuming addiction I’ve had in years (thanks a lot Jeremy). It is a nice balance of professional and personal posts, useful enough for folks in the search business and authentic enough to feel like you know Jeremy and even come to like him. In short, an enjoyable and successful blog.
In his recent post, he asked:
I may be in the market for a relatively cheap quad-band GSM phone that can be used in various foreign countries. Nothing fancy. I just need something I can drop a SIM card into and make calls and maybe send a few text messages.
The trouble is that I have no idea where to buy one and what to look out for. I’ve seen some available on Amazon.com and, as expected, they seem to be all over eBay. Plus there are various on-line stores that seem to specialize in selling unlocked GSM phones to people in the United States. But I don’t know which are trustworthy.
So if you wanted a handy little Motorola or Nokia GSM phone, where would you buy it on-line? And, if you happen to have a preference, which phone(s) would you look at or try to avoid?
In case you’re wondering, I’ve been a Verizon (CDMA) user for a few years now and have no plans to change that. I’m just looking for something that’d be handy when I and others travel.
Amazing. This is functionally identical to Doc’s VRM Inquiry looking for a new phone back in November 2006:
Okay, I’m gonna ditch my Verizon Wireless account, and the silo’d-to-hell Palm 700p that goes with it (and not with other providers). The Palm is nice in some ways, but its too heavy, too crashy, too lousy at too many things I depend on. (Dialing, for example.)
I want a phone that is GSM-based (so it works overseas as well as in the U.S.), works across as much of the U.S. and Canada as possible (Verizon has been a disappointment in this respect), has a GPS, and has an easy-to-use UI. I don’t care about PDA functions, ringtones (I like the old Western Electric bell ring, though), or camera functions. I like keys that are easy to read and use, and an address book that’s easy to synchronize with a computer. It would be nice, for personal reasons (I work for Linux Journal), if it ran on Linux. I’d rather it not (for the same reason) run on Windows. Mostly I just want it to be a good GSM phone with a GPS. And I’m willing to let the GPS function slide, just to get a good phone.
And I’m ready to buy it.
So, who gets my money, and for what? (The Nokia E62 has been recommended, but I’m not sure the phone keys aren’t too small.)
Consider what these posts have in common:
posted on high-traffic blogs
written by sophisticated Internet power users
requests for cell phone and cell phone vendors
considerable detail about what they want and don’t want in terms of features
lack of certainty about which product meets their needs best
lack of certainty about where to buy that product
a request for help from their readership
customers ready, willing, and able to buy, right now
What’s fascinating to me is that both of these posts are clear VRM gestures well before any sort of VRM infrastructure is built to handle it. Doc’s worked. And Jeremy’s probably will also, because he has a large enough, friendly enough, and sophisticated enough readership to help him find a phone that fits his needs.
I know that two VRM RFPs don’t make a trend, but for them both to show up in my feed reader and be for GSM phones by sophisticated guys who know as well as most how to research and shop online… I believe it is a bellwether of things to come.
I’ve written a few times about the VRM personal RFP. From my view it is one of the “low hanging fruits” of the VRM world. Shopatron has already demonstrated a viable approach for turning confirmed orders over to a streamlined marketplace of vendors. Now both Doc and Jeremy are showing that even without that streamlined marketplace, for some purchases, just blogging a psuedo-RFP is better than the alternatives.
Many people have raised criticisms about personal RFPs.
People don’t want to do all that work
People don’t want to wait for responses
You can’t change vendor behavior
It’s too complicated
Vendors can’t handle open-ended RFPs
There’s a catch-22: without orders, no vendors. without vendors, no orders.
On the surface, these all seem like valid obstacles. But each one is either untrue or irrelevant.
First, for some purchases, people already do an incredible amount of work. I’ve interviewed a TV buyer who spent 18 months gradually, slowly researching his options before finally purchasing a new 42″ plasma TV. And it took a full three months after he was financially committed to buying it to actually settle on the model and vendor. Another interviewee spend 28 hours over four days researching travel and work options for teaching abroad. She knew what she was looking for, had plenty of experience, and found that this was the kind of research she needed and was willing to do to plan and create her trip.
Clearly, people are willing to put a lot of work into these kinds of purchases. These are complex searches. And it seems clear to me that there are a lot of these kinds of searches that could be made easier with the right tools, including VRM personal RFPs.
Second, there is no reason that a personal RFP requires any more waiting that submitting an HTTP request. Sure, some models of RFP fulfillment have a certain amount of delay, especially if vendors need a human to process the order. I don’t know the reason for the delays at Priceline, but at Shopatron this delay is effectively hidden from the user. Shopatron’s approach works because they have a fixed set of products and vendors–and a fixed price–where they can assure timely delivery: the delay gets eaten up in the shipping and handling rather than in the purchasing.
Once more scalable VRM protocols are defined, vendors will be able to participate in real-time. If Hertz, Avis, and Enterprise are all in the VRM marketspace, there isn’t any reason they couldn’t automate responses to RFPs for rental cars. It’s not automated yet, but then again, neither were any of the direct to consumer shopping services in 1993. The web changed all that, with realtime responses for product inquiries, orders, tracking, returns, and more. So, count on a large number of VRM RFPs creating responses in seconds, especially in well-established markets like travel and real estate.
Third, vendor’s behaviors change all the time. The World-Wide Web changed a lot of things. And so has Shopatron. While new innovations always face challenges the more they disrupt current practices, there are always vendors willing to be first movers if the payoff potential is large enough. There will also be vendors who will fight tooth and nail before they do business any different than what got them where they are today. That’s just part of the challenge. We not only have to find the right vendors, we have to find the right solution, the right way to communicate it, and the right way for them to say “yes.” That’s called sales. Fortunately, I can think of nothing more motivating to a vendor than a confirmed, qualified, and capable customer.
Fourth, it is becoming increasingly clear that people demand solutions to complicated problems. Of course, we want it to be as simple as possible, but we are well beyond the early days of the world wide web where people were learning how to click on hyperlinks. People have sophisticated needs and while the simplicity of the Google search box made a huge difference in how we surf the web, even Google knows they have to move beyond that. We know that getting the right answer can’t happen magically. We are decades away (at least) from mind-reading computers that distill basic needs into real-world products and services. Some how, some way, we must express our intent so that people can respond, even better if computers can respond automatically. The challenge is figuring out how to package RFPs like Doc’s and Jeremy’s without losing the ease, flexibility, and specific vagueness, boundaries that were clear but within which many options would work. The technical challenge is significant, but I don’t believe it is too complicated for users. Instead, I suggest that the solutions we’ve seen so far might be too complicated for users. Sort of like the Internet before hyperlinks.
Fifth, while many vendors can’t handle open-ended RFPs, that doesn’t mean the entire system fails. It simply means that that vendor can only respond to limited RFPs. An unnamed car rental agency responded to Doc’s presentation of VRM with the certainty that they could never respond to all the varied options that people ask for. Their inventory management systems simply don’t have that kind of flexibility. However, that doesn’t mean that they couldn’t respond to those RFPs that fit within their parameters or even respond to partial hits with proposals that clearly specify their limitations. When the waiter apologizes because the restaurant is out of your favorite beer, do you leave the restaurant? Not usually. A VRM RFP needs to enable a sales conversation to take place, one that affords vendors a chance to suggest partial RFPs based on existing capability and capacity. High-end vendors who specialize in custom, high margin requests, would be free to propose a solution that meets the full RFP. Ultimately, the user selects which vendor gets the order.
Sixth, this kind of catch-22 is actually a network effect. It is true that in the beginning there won’t necessarily be a lot of users to attract vendors and that as vendors start to participate, there will be limits on the types of products and services available. This is a catch-22. However, as new vendors join, it becomes increasingly attractive to customers. And the more customers, the more attractive it becomes to vendors. And when this is delivered in an open-standard, open-network environment, the runaway tipping point can happen quickly and in many different markets at once. So, rather than complain about the catch-22, find those seed markets where vendors and customers can readily see the value, and build services to connect people with vendors. There will be early adopters. In the right markets, those adopters will trigger a network effect that catalyzes the entire marketspace, just as the World-Wide Web grew from academia to technology markets to technologists to eventual mainstream adoption.
I don’t know if Jeremy realized he was making a VRM gesture or if he would even consider his post an “RFP,” but perhaps he will see this post and think a bit about how VRM is addressing something fundamentally new, and yet, incredibly close to what we people already need.
The $64,000 question: why didn’t Jeremy just search Yahoo!?
There’s a lot of room to go in search… and NONE of the current search providers–not just Yahoo!–could have answered Doc or Jeremy’s inquiry more effectively than their blog posts. In fixing that problem lies the hope of VRM personal RFPs.