People: on the edge

XIII.4 July + August 2006
Page: 51
Digital Citation

Tagging the world

Lars Holmquist

back to top 

Many interaction technologies experience a brief period of hype in industry and academia, after which they are summarily forgotten. But as the technological landscape changes, some make a surprising comeback.

One such technology is electronic tagging. Tagging has been around since the barcode; it simply means that you place a machine-readable label on a physical object. A big advantage of tagging is that the actual modification you have to perform on the object is minimal, as is the cost. The disadvantage is that the object still does not do anything on its own—you need a tag reader, a connection to a database of tags, and some way of displaying the results to get anything useful out of it.

The most common ways of tagging involve visual codes, like the barcodes you see in supermarkets, and radio frequency or RFID tags. Visual codes are very cheap and can be incorporated easily in package design or printed on labels, but they must be scanned actively using a camera or code reader. RFID tags are comparatively expensive but can be hidden inside an object and scanned at a distance. In industry, tagging is already a fact of life; companies like Wal-Mart and FedEx have seen their business process change dramatically with the introduction of the ubiquitous tagging of everything they handle.

In the late `90s, the most promising use of tagging seemed to be associating physical objects with digital information, in particular the emerging World Wide Web. For instance, my research group came up with WebStickers—barcode stickers that could be attached to everyday objects. With these, users could easily associate any stickered object with a Web address. You could, for instance, put an augmented Post-It note on your colleague's door to remind her of a site you talked about, with the note serving as a "physical Web bookmark," or you could associate an object such as a coffee cup with an online activity, like reading the morning news. Others that explored similar ideas at the time included Xerox PARC, with RFID tags; HP Labs and their CoolTown project; and the MIT Media Lab, which was crawling with demos showing how tagged physical objects could be associated with digital information.

There were also several ambitious attempts to introduce tagging in consumer products. The CueCat, which was given away for free in stores in the early 2000s, was a cute barcode reader that you attached to your PC. You could then scan a barcode on a magazine page or a product and get taken instantly to the relevant Web page. Another example was ConnectThings, which promised to connect everything with a barcode to an online database. Their first application, developed in collaboration with Swedish medical authorities, linked the barcodes on medicine packaging to an Internet information directory.

Only a few years later, all these companies have vanished, and tagging is no longer a hot topic for research demos. In retrospect, the reason is clear. Why take the trouble of bringing an object to your computer and scanning it? By the time you get it there you have probably already lost interest, and anyway it's easier to just type a few keywords into Google.

But there is really nothing wrong with the idea of tagging—it's just that the desktop computer was the wrong platform. What we really need is a small mobile device that incorporates a tag reader, a display and an online connection in a single package—an everyday item that you bring with you in all situations.

That's right: a camera phone!

While users in Europe and the US are still getting used to the idea of using their phones as Internet devices, mobile tagging is a fact of life in Asia. A system called QR Codes provides visual tags that are readable with the camera built into any modern phone, and easy to generate and print. The codes can hold hundreds of characters, more than enough for a complicated Web address.

QR Codes appear in the most surprising places in Japan. They turn up in magazines and on advertising signs in the subway. You find them on business cards, there are greeting cards you can scan to get an automatic message to send along, and you even end up with one in your passport after passing immigration!

It gets really interesting when tags turn up "in the wild." In Kyoto, the ancient city that is home to thousands of temples, I found QR Codes on the timetable at a bus stop, linked to real-time data of when the next bus would come. Another sign held QR-encoded links to information about famous attractions in the city. Most dramatically, a gigantic QR Code hovered on a billboard over a major Tokyo fashion store! Here, we can really see the power of mobile tagging—providing complementary information when and where you actually need it, rather than at the comfort of your desktop.

The next step for tagging may be better, more colorful tags that are easier to integrate into existing design, like the Korean ColorCodes system. It should only be a matter of time before Western phone companies launch tagging systems of their own; whether they catch on remains to be seen. But things will get really exciting when electronic tagging is combined with another tagging explosion: the one on the Web, where myriadusers right now are creating searchable "folksonomies" by collaboratively tagging photos and Web pages on Flickr,, and many other sites. When this movement of semantic tagging breaks out of the desktop computer and into the real world, spurred along by camera phones and other mobile technology, the possibilities are endless.

back to top  Links


CoolTown project

CueCat barcode reader

QR Code homepage


back to top  Author

Lars Erik Holmquist

About the author

Lars Erik Holmquist is the leader of the Future Applications Lab at the Viktoria Institute in Goteburg, Sweden. He is interested in innovative interactive technology, including tangible interfaces, informative art, mobile media, and autonomous systems. He was general chair of UbiComp 2002, the international conference on ubiquitous computing, and is an associate editor of the journal Personal and Ubiquitous Computing.

back to top  Figures

F1Figure 1. WebStickers was an early demonstration of how physical objects could be linked to the Web with optical tags.

F2Figure 2. In Japan, QR Codes readable by mobile phones are linked to sightseeing tips, bus timetables and other sources of online information.

back to top 

©2006 ACM  1072-5220/06/0700  $5.00

Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, to republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee.

The Digital Library is published by the Association for Computing Machinery. Copyright © 2006 ACM, Inc.

Post Comment

No Comments Found