OU researchers design trolley handle to measure global consequences of food shop

Do you consider the global consequences of what you put in your shopping trolley at the supermarket? Researchers at The Open University have designed a trolley handle which does just that – informs shoppers of the costs and benefits of their food choices.

The team has designed, built and tested a lambent shopping trolley handle which ‘nudges’ people to make more informed decisions when they shop for food – by measuring food miles as items are scanned and placed in the trolley.

When a shopper scans a product they can assess how their choices compare to the social norm. The handle, which just clips onto any regular shopping trolley handle, is mobile, easy to use and boasts a simple yet fully functional lambent display mechanism which conveys relevant information when making shopping decisions - that can often be tricky to find on food labels and packaging.

“Overall, we found that the lambent shopping handle generated a significant nudge effect, influencing what products people selected. When using the device, 72 per cent of the products had lower mean food mileage than the products chosen when using a normal shopping trolley,” says Vaiva Kalnikaitė, a visiting research fellow to the Open University, working specifically on the CHANGE project and leading the handle design, build and evaluation.

Shoppers make fast and frugal decisions
The Lambent Trolley Handle falls under the CHANGE project which explores how technologies can be used to change and influence human behaviour, with particular focus on the environment. The CHANGE project is a collaboration between the OU, Goldsmiths, Nottingham University and Sussex University, which was funded by the Engineering and Physical Sciences Research Council between November 2009 and July 2011. The Lambent Trolley Handle was created and evaluated in collaboration with colleagues from Microsoft Research Cambridge, UK; University of Bath, UK; Indiana University, USA; and DFKI GmbH, Germany.

It provides salient information about the food miles for various scanned food items, represented by LEDs lights on the handle and a changing emoticon – happy face for good, sad face for bad - comparing the average miles of all the products in the trolley against a social norm.

“When evaluated in situ, the lambent handle display ‘nudged’ people to choose products with fewer food miles than the items they selected using their ordinary shopping strategies. People also felt guilty when the average mileage of the contents of their entire shopping trolley was above the social norm,” says Vaiva.

How do you do your shopping?
The project delves into how people make reasonable decisions given time constraints, limited information and resources to help them. Research shows that most shoppers make fast and frugal decisions; they make choices based on what is recognised and ignore information which can’t be processed quickly and easily.

“For example, in a supermarket, shoppers tend to make snap judgments based on just a few salient cues (low price, recognised brand and attractive packaging) and they rarely take time to read product information labels,” says the OU’s Professor Yvonne Rogers, principal investigator on the CHANGE project, who also helped design and evaluate the handle.

“People who read labels on products still did read the labels but it took them less time and if the information wasn’t there they were happy to use the handle. If they couldn’t find the information they wanted on their favourite brands, say cheese for example, they were happy to scan items and let the trolley handle decide for them, because it was quicker,” added Jon Bird, research fellow on the CHANGE project, who also worked on the handle design.

The handle has been developed to be fairly inconspicuous, so shoppers weren’t self-conscious using it, and which displayed information that could be seen at a glance with a series of coloured LED lights.

“It needed to be light and simple to attach, so we built a fully functional independent device that clips on to a shopping handle and comprises a small display, a series of LEDs that are connected to an embedded barcode reader and other electronics. And then we went shopping!” explains Vaiva.

Eighteen participants took part in the research – eight female and 10 male, aged between 23 and 65, from varying backgrounds, and all shopping took place in Asda, chosen because of its locality to the OU and because of the product information available on its website, which was poured into the trolley handle’s database.

Evaluating shopping behaviour
Each participant shopped once using the lambent trolley handle (nudge conditions) and once using an ordinary, unmodified shopping trolley (controlled condition). They were given a shopping list comprising of items such as Brie, demerera sugar, dark chocolate, honey and chillies.

“When selecting items for the shopping lists, we tried to pick products that varied in their food miles and organic properties. For each product on our shopping lists, there were at least two choices for origin, for example, local (UK) and close (European) or local (UK) and very far (rest of the world). However, we also had a few products where the country of origin was less important, such as Brie cheese where all the alternatives came from France,” said Vaiva.

“We asked people to shop with and without the handle to see how that affected shopping behaviour. Those who used the handle first got used to it and missed it when they shopped without it. It also changed basic things about the way they shopped – they took the trolley closer to the products, rather than parking it and coming back to it. They always stayed much closer to the trolley than those shopping without it” she added.

Khaled Bashour, a visiting research fellow to the OU, who helped conduct the evaluations with a team of volunteers in Asda, added: “For some items, shoppers had to make decisions about what was most important to them when buying food. Organic honey, for example, tends to come from Mexico which has high food miles, so there was no option to buy local organic honey or even honey from the UK. So it came down to price in the end; people tended to make the decision between organic versus food miles by going for what was cheapest.

“There’s a brand of sugar that comes from the UK although it doesn’t actually say that on the packaging, but it’s double the price of other sugars. So the handle helped people to learn why it was priced higher and possibly nudge them to spend more knowing it was local. Without that knowledge they would have simply dismissed it as too expensive” he added.

Watch the fest and frugal shopping challenge and see the lambent trolley handle in action...

The results of the research have been written up into a paper but proved hard to analyse; some products sold out so not all volunteers were able to shop for exactly the same items.

And while the project and funding has now come to an end, the team hopes to continue work with the shopping handle, which can be programmed to look for a range of data including salt content, origin and organic properties.
 
“We’d really like to do more work with the shopping trolley handle,” says Vaiva. “We’d also be interested in seeing how families use it and how children interact with it. Perhaps they could influence how parents shop and help them understand issues like food miles and also make shopping more of a family experience.”

The research is also on its way to China - the team will give a presentation and a live demonstration of how the shopping trolley handle works at the Ubicomp’11 conference in Beijing this September. Furthermore, they are currently liaising with another UK supermarket chain over future use of the handle and its technology, with more testing potentially being carried out with colleagues at DFKI GmbH in Saarbrϋken, Germany.

Who was involved?
Vaiva Kalnikaitė, visiting research fellow on the CHANGE project; Professor Yvonne Rogers, head of Pervasive Interaction Lab at the OU, principle investigator on the CHANGE project; Jon Bird, research fellow on the CHANGE project; Nicolas Villar, researcher at Microsoft Research Cambridge; Khaled Bachour, visiting research fellow on the CHANGE project; Professor Steven Payne, University of Bath, UK; Professor Peter M. Todd, Indiana University, USA; Johannes Schöning, research fellow at DFKI GmbH, Germany; Professor Antonio Krüger; DFKI GmbH, Germany; Stefan Kreitmayer, PhD student at Pervasive Interaction Lab at the OU.