adversarial correction: A portrait of humanity in the purchases we make

Jim Giles, consultant

(Images: Courtesy of Adrian Lopez and ZERO1 Biennial)

A software visualisation of eBay trading, created for the Zero1 Biennial festival, shows how companies? records are a window on ourselves

WHAT does the word "data" mean to you? Unless you are a scientist or computer programmer, the term probably conjures up something rather dull, like an agricultural quota or an Excel file. "When I talk to people about data, they say 'spreadsheet'," says software artist Jer Thorp. That's a problem, he adds, because a lot of important data sets are also something else: cultural artefacts that we all have a share in.

I'm speaking to Thorp outside the Californian offices of eBay, a company that controls some of the most culturally interesting data produced since the birth of the internet. The value of goods traded on the site last year averaged $2000 per second. More than 100 million people use PayPal, eBay's sister company, to send and receive money. And within the records of these transactions are innumerable stories about peoples' lives. "eBay is this giant thing that's being written," says Thorp. "It's full of people and places and objects."

We are looking at Before Us is the Salesman's House, the output of software Thorp developed in collaboration with Mark Hansen, a statistician at the University of California, Los Angeles, for the technology-themed arts festival ZERO1 Biennial.

Each iteration of the work takes the viewer on a tour through eBay's data universe. The process starts with a book - a different one each time. The system finds a digital version of it and extracts the names of objects from the text. Next, the software searches for those objects on eBay, generating a tour that hops through a map of the US, showing images of the items for sale alongside the seller's location. Finally, the software picks a book that was sold recently on eBay from the last town on the tour, and the cycle starts again.

Thorp settled on using books as "tour guides" after picking up a copy of Death of a Salesman by Arthur Miller. The title of Thorp's piece is one of the first lines in Miller's text. Soon after, the stage directions mention a table, chairs and refrigerator. The link between a salesperson and objects "just felt so perfect" for eBay, says Thorp.

On one level, the work highlights unexplained clumps of activity: a spike in kitchenware sales in one small town, perhaps, or another that appears to focus on sporting goods. But Thorp hopes that it will also provide a window on the human stories within eBay's databases, and so make people think about the data we leave behind on the internet.

The output is displayed on a screen outside the company's offices in San Jose, California. "I imagine someone sitting there at night, meditating on the system," says Thorp.

eBay's records are of great value to today's social scientists, and will be sought after by tomorrow's historians. The same goes for data held by Google, where, among other things, people leave a record of their interests and concerns every time they search. Facebook data may hold the key to understanding social networks, while blogging platforms capture the evolution of language.

This information is created by individuals and is of potential value to society, yet it is owned by corporations that are under no obligation to preserve it for posterity. Thorp and Hansen's work is a challenge to academics and policymakers, lest the cultural value of the data goes to waste.

Before Us is the Salesman's House by Jer Thorp and Mark Hansen, ZERO1 Biennial, Silicon Valley, California, until 8 December