=Paper=
{{Paper
|id=None
|storemode=property
|title=The Augmented Shopping Trolley: An Ambient Display To Provide Shoppers with Non-Obvious Product Information
|pdfUrl=https://ceur-ws.org/Vol-722/paper1.pdf
|volume=Vol-722
}}
==The Augmented Shopping Trolley: An Ambient Display To Provide Shoppers with Non-Obvious Product Information==
https://ceur-ws.org/Vol-722/paper1.pdf
The Augmented Shopping Trolley: An Ambient Display To
Provide Shoppers with Non-Obvious Product Information
Jon Bird, Vaiva Kalnikaité and Yvonne Rogers
Pervasive Interaction Lab
The Open University
Milton Keynes, MK7 6AA, UK
{j.bird, y.rogers}@open.ac.uk, vaivak@gmail.com
ABSTRACT information about the global consequences of their
The Augmented Shopping Trolley consists of an ambient consumer decisions [2]. Our goal is to provide ‘non-
handlebar display connected to a scanner. When a shopper obvious’ nutritional, ethical and environmental product
scans an item the handlebar lights up to provide them with information, that is, information that is not immediately
information about the product, such as its nutritional, obvious from an item’s packaging or label, in a form that is
ethical or environmental attributes, that are not obvious as salient as the features that typically inform consumers’
from its packaging or label. The system is designed to decision making. The Augmented Shopping Trolley (Figure
seamlessly integrate with a shopping experience: it uses 1) is designed so that it fits as seamlessly as possible into a
familiar supermarket technologies; it keeps both of a supermarket shopping experience. We use familiar
shopper’s hands free; and the simple ambient display supermarket technologies: augmenting a standard shopping
facilitates the ‘fast and frugal’ decision-making typically trolley by attaching a scanner and embedding an ambient
observed in a supermarket. Our initial lab-based study display in the handlebar. This gives our system two
shows that the display can be understood at a glance and advantages over using mobile devices to provide product
used to select items based on a product’s nominal properties information. First, the trolley scanning technology is faster
(for example, it is organic), ordinal properties (for example, [4] and second, because the ambient display is built into the
it has low, medium or high food miles), as well as a trolley handlebar a customer’s shopping experience is not
combination of the two at the same time. Where as usability disrupted by having to repeatedly access and store a mobile
was the focus of our initial design, ethical issues have come display. Underhill [10, see chapter 4] emphasizes the
to the fore as we develop the system for use in importance of having both hands free during shopping.
supermarkets and we discuss how these are influencing our
design.
Author Keywords
Persuasive technologies, ambient display, shopping,
product information, ethics.
ACM Classification Keywords
H5.m. Information interfaces and presentation (e.g., HCI):
Miscellaneous.
INTRODUCTION
In a supermarket, shoppers tend to make snap judgments
based on just a few salient cues (low price, recognized
brand and attractive packaging) and they rarely take time to
read product information labels [7]. However, recent Figure 1. The Augmented Shopping Trolley display consists of
consumer surveys indicate that shoppers want more 16 LEDs embedded in the handlebar, each of which can be set
to green, red or orange
Permission to make digital or hard copies of all or part of this work for Our approach to designing an effective ambient display,
personal or classroom use is granted without fee provided that copies are first outlined in [9], is motivated by studies of ecological
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, rationality which investigate how people make reasonable
or republish, to post on servers or to redistribute to lists, requires prior decisions given the constraints of limited time, information
specific permission and/or a fee. and computational resources that characterize most real
Copyright © 2011 for the individual papers by the papers' authors. world situations [6, 8]. This research indicates that most
Copying permitted only for private and academic purposes. This volume
is published and copyrighted by the editors of PINC2011..
natural decision making is made on the basis of ‘fast and (idle state) to a half second sweeping movement of orange
frugal’ heuristics – short-cut strategies where people ignore that indicates scanning is in progress. There is then a beep,
most of the available data and instead focus on the most as typically heard at a checkout counter, to signal that
useful information and process it quickly. Often people scanning is completed and the display then changes to a
make a decision based on a single reason as this strategy is new state that provides relevant information about the
quick and simple and avoids having to weigh up trade-offs product. If the display is configured to show a nominal
between multiple and potentially conflicting options. This property of the product, then it flashes green if the property
approach is not rational in certain environments, namely, is present and shows the idle state if it is not. If the display
those where available pieces of information are is providing ordinal information about the product, the
approximately equally useful. However, in a shopping display employs a bar graph metaphor, with the number of
environment, the distribution of information usefulness is red pixels indicating the degree to which an item has a
highly skewed, that is, the most useful piece of information property. Specifically, if an item has a low degree of a
is a lot more important than the second most useful, which property then pixels 1-3 turn red and 4-16 turn green; if
in turn is considerably more important than the third, etc. medium then pixels 1-8 turn red and pixels 9-16 turn green;
Our handlebar ambient display consists of just sixteen and pixels 1–13 turn red and 14-16 turn green if the item
LEDs. When a shopper scans a product, a few pieces of has a high degree of a particular property. Finally, both
non-obvious information, such as whether it contains nuts, these representations can be combined to show the value of
is fair trade or has low food miles, are displayed as a salient a nominal and an ordinal property at the same time. In our
pattern on the display. study, after a participant selected or discarded an item, the
display changed back to the all green idle state.
Given that information salience influences a person’s
behaviour unconsciously [1], rather than through rational
LAB-BASED SYSTEM EVALUATION
reflection, this raises ethical concerns about the Augmented 5 adults (1 female, 4 male, aged between 20 and 40) took
Shopping Trolley, chief of which is that this system could part in a lab-based evaluation of the Augmented Shopping
potentially manipulate people into behaving in ways that Trolley. Each participant completed 12 shopping scenarios
they would not otherwise do, and furthermore, that they where they were asked to pick up and scan 5 items of a
might not be aware that they had been manipulated. This particular product type and only select those items that met
concern, and also issues to do with privacy and clarifying specified criteria. A scanner was attached to the shopping
how our system benefits shoppers, form the ethical trolley (Figure 1) but was non-functional and the handlebar
considerations that are influencing how we deploy the display was changed using a Wizard of Oz methodology.
Augmented Shopping Trolley in a supermarket.
On the basis of the changes in the patterns on the handlebar
The paper is structured as follows: first, we describe the
display, participants had to decide whether to select the
display hardware and how it conveys product information; item and place it in their trolley or discard it and place it on
second, we describe a lab-based evaluation of the system an adjacent table. Since this was an exploratory study, we
that demonstrates the efficacy of the ambient handlebar were intentionally vague about the operation of the ambient
display for conveying non-obvious product information; display as we wanted to see whether participants could
and third, we describe the ethical issues that are informing understand it intuitively. We only told participants that the
the development of the system for use in supermarkets. display patterns would change depending on whether a
product had a specific property (yes/no), the degree to
AMBIENT HANDLEBAR DISPLAY DESIGN
which a product had some property (high/medium/low) or a
The handlebar display was designed to provide shoppers
combination of the two. Participants were allowed to scan
with salient and easy to read information about a scanned
the items as many times as they wanted and in any order,
product’s nominal properties (for example, whether it is
before they made their decision about whether to select a
organic or contains nuts), its ordinal properties (for
particular item. We used 4 product types: milk; breakfast
example, if it has low, medium or high food miles), as well
cereal; wine; and juice. Each shopping scenario used one of
as a combination of the two at the same time. We
the product types and participants were asked to select from
constructed the display by attaching 16 bicolour LED units
5 different items. For example, select those bottles of wines
to a piece of wood inside a transparent plastic tube (Figure
that meet the specified criterion (fair trade) and put them in
1). This replaced the plastic handlebar in a standard
the trolley, and place the others on the discarded items
shopping trolley. The LEDs are controlled using 2
table. Each of the items was a real product but we masked
TLC5940 chips (Texas Instruments) that are driven by an
any product information on the packaging and told
Arduino microcontroller. In our lab-based study this is
participants to only use the handlebar display to decide
attached via a USB cable to a laptop running a Processing
whether they should select an item or not. The experimenter
application. Each LED unit can be set to red, green or
playing the Wizard of Oz role sat at a table on which the 20
orange (when both the green and red LEDs are on). Each
shopping items were grouped by product type. Each item
time a product is scanned, the display changes in the
was individually numbered so that the experimenter could
following way. First, it goes from an all green background
change the display appropriately when the participants use and were able to quickly read it even though they were
scanned a particular item. not given explicit information on the meaning of the display
patterns. Only two participants scanned items more than
In the first 4 shopping scenarios the handlebar display
once and this was exploratory activity at the beginning of
indicated whether a scanned item had a particular nominal
the evaluation when they were seeing how the interface
property or not: whether a milk product was organic;
worked.
whether a breakfast cereal contained nuts; whether a bottle
of wine was fair trade; and whether a carton of juice
ETHICAL ISSUES AND FURTHER DEVELOPMENT
contained added sugar. In 2 of these scenarios the
Whereas usability issues informed our initial design, ethical
participants had to select items that had a particular
considerations are shaping the development of the
property and in the other half they had to discard items if Augmented Shopping Trolley for use in supermarkets. This
they had a particular property. For example, in the first is because our ambient display not only provides salient
shopping scenario participants had to select a milk product product information for shoppers, but also potentially
if it was organic and discard it if it was non-organic; in the influences what they purchase. The use of persuasive
second shopping scenario participants had to select a technologies raises ethical concerns for many people. For
breakfast cereal if it did not contain nuts and discard it if it example, Page and Kray [3] used an online questionnaire to
did. investigate people’s views on the ethics of using persuasive
In the next stage of the evaluation, the participants technologies to encourage healthy living. 72 participants
completed 4 shopping scenarios where the display indicated rated the ethical acceptability of a number of different
whether a product contained a low, medium or high value scenarios which varied in 3 different factors: whether a
of a particular ordinal property. The task was to select items participant chose to use the technology or an external
that had a specified property to a particular degree. agency initiated its use; whether there was a clear benefit
Specifically, participants were asked to select milk with a for the participant or not; and the technology used (text
medium fat content, cereals with a high sugar content, wine messages to the participant’s mobile phone; public
with low food miles and juice with a medium water content. announcements in the participant’s location; Facebook
In none of these scenarios were participants asked to messages; restrictions on the participant’s bank account;
discard items if they had properties of a particular degree. and electric shocks). The results indicated that the majority
The final 4 shopping scenarios tested whether participants of the participants viewed the use of persuasive
could understand the display when it simultaneously technologies in most of the questionnaire scenarios as
showed information about both a nominal and an ordinal unethical. When there was no clear benefit to the
property of a scanned item. Participants were asked to participant, mobile phone were considered the most ethical
select milk that was organic and low fat, cereals that persuasive technology. However, approximately the same
contained nuts and had a medium sugar content, juice that proportion of participants (40%) considered them very
had added sugar and high water content and wine that was ethical or ethical as the proportion that considered very
not fair trade and had medium food miles. Only in the wine unethical or unethical when. A large majority of
scenario did participants have to reject items on the basis of participants found the other technologies very unethical or
information about a nominal property of the product. unethical. In scenarios where the use of a technology would
clearly benefit the participant, for example, save their life,
USABILITY RESULTS then this usage was considered slightly more ethical than
4 out of the 5 participants were able to interpret the ambient the cases where the technology did not benefit the
handlebar display and complete all the tasks without any participant. However, it is not clear whether these
mistakes. The other participant made one consistent error in differences were statistically significant. When people were
2 of the first shopping scenarios where the task was to able to freely choose whether to use a persuasive
discard items if they had a particular nominal property: they technology or not, then texts, public announcements and
selected, rather than discarded, them, but did not repeat this Facebook messages were considered ethical by the majority
error in the final shopping scenario which also required an of respondents, in comparison to the situation where the use
item to be discarded if it had a particular nominal property. of the persuasive technology was initiated by an external
Several participants reported that they found the tasks entity (for example, the UK’s National Health Service).
where they had to discard items with particular properties Electric shocks and bank account restrictions were
more difficult and it did seem to increase the cognitive load considered very unethical or unethical by the majority of
in all participants, resulting in a slightly slower response respondents, even when a participant chose to use them.
time (approximately 2 seconds, rather than 1 second for the
Page and Kray’s findings seem to concur with a central
other conditions). This could be due to the colours used in
factor identified by applied philosophical analyses of
the display: a nominal property is indicated by a green
ethical behaviour, for example, the use of persuasion in
blinking display, a colour that many people associate with
advertising [5]. Namely, the ethics of an action are
positive properties, rather than ones that should be avoided.
determined, to a large degree, by the extent to which that
All participants reported that the display was intuitive to
action impacts on an individual’s autonomy, that is, their
capacity to choose how to act and determine their own life. nominal and ordinal properties of a scanned product. Our
Page and Kray’s research also highlights that privacy and display is intuitive to use and requires no training.
the extent to which a participant benefits are important Participants find it easier to select items when they have
issues for determining the ethical acceptability of desirable properties than to not select them because they
persuasive technologies. All three of these ethical have undesirable properties. The Augmented Shopping
considerations (autonomy, privacy and benefits) are Trolley makes non-obvious nutritional, ethical and
shaping the development of the Augmented Shopping environmental product information salient to shoppers and
Trolley. facilitates the fast and frugal decision making typically used
in a supermarket. Some of the global consequences of
To ensure shopper’s autonomy, they will be free to decide
selecting particular products can now be made salient to
whether they use the Augmented Shopping Trolley and also
shoppers at the point of decision making, potentially
able to choose which particular non-obvious product
facilitating changes in consumer behaviour. We argue that
information they want to be informed about. Given that
our system is an ethical persuasive technology as it
users can configure the system to provide different product
enhances the ability of shoppers to buy choose products in
information, privacy is not compromised, even though the
accordance with their individual values.
handlebar will be visible to other shoppers, as they will not
understand what particular LED patterns mean. Some of the
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CONCLUSIONS Simon and Schuster: New York. 2009
Our lab-based study shows that participants can rapidly
read a shopping trolley handlebar display to determine both